diff --git a/app/components/storage/BackupJobTable.vue b/app/components/storage/BackupJobTable.vue
index 959e009..d755b32 100644
--- a/app/components/storage/BackupJobTable.vue
+++ b/app/components/storage/BackupJobTable.vue
@@ -26,7 +26,8 @@ function typeLabel(type: BackupJobItem['type']): string {
   const map: Record<BackupJobItem['type'], string> = {
     full_export: t('storage.backup.jobTypeExport'),
     full_restore: t('storage.backup.jobTypeRestore'),
-    backend_sync: t('storage.backup.jobTypeSync')
+    backend_sync: t('storage.backup.jobTypeSync'),
+    site_sync: t('storage.backup.jobTypeSiteSync')
   }
   return map[type]
 }
diff --git a/app/components/storage/SiteSyncCard.vue b/app/components/storage/SiteSyncCard.vue
new file mode 100644
index 0000000..3e9c9ef
--- /dev/null
+++ b/app/components/storage/SiteSyncCard.vue
@@ -0,0 +1,256 @@
+<script setup lang="ts">
+import type {
+  SiteSyncDirection,
+  SiteSyncRequest
+} from '~/types/backup'
+
+const props = defineProps<{
+  busy: boolean
+  disabled?: boolean
+  activeJob?: {
+    progress: number
+    total: number
+    message: string
+    payload: Record<string, unknown>
+  } | null
+  resumableJob?: {
+    id: string
+    payload: Record<string, unknown>
+  } | null
+}>()
+
+const emit = defineEmits<{
+  sync: [body: SiteSyncRequest]
+}>()
+
+const { t } = useI18n()
+const targetBaseUrl = ref('')
+const token = ref('')
+const conflictMode = ref<'skip' | 'overwrite'>('skip')
+const direction = ref<SiteSyncDirection>('push')
+
+watch(() => props.resumableJob, (job) => {
+  if (!job) return
+  direction.value = job.payload.direction === 'pull' ? 'pull' : 'push'
+  if (typeof job.payload.targetBaseUrl === 'string') {
+    targetBaseUrl.value = job.payload.targetBaseUrl
+  }
+}, { immediate: true })
+
+const canSubmit = computed(() =>
+  !props.busy
+  && !props.disabled
+  && Boolean(targetBaseUrl.value.trim())
+  && Boolean(token.value.trim())
+)
+const canResume = computed(() =>
+  !props.busy
+  && !props.disabled
+  && Boolean(props.resumableJob)
+  && Boolean(token.value.trim())
+)
+const fileProgress = computed(() => {
+  const payload = props.activeJob?.payload
+  return {
+    synced: Number(payload?.filesSynced ?? 0),
+    total: Number(payload?.totalFiles ?? 0)
+  }
+})
+const isPull = computed(() => direction.value === 'pull')
+const directionSubtitle = computed(() => (
+  isPull.value
+    ? t('storage.backup.siteSyncPullSubtitle')
+    : t('storage.backup.siteSyncPushSubtitle')
+))
+const endpointLabel = computed(() => (
+  isPull.value
+    ? t('storage.backup.siteSyncSource')
+    : t('storage.backup.siteSyncTarget')
+))
+const tokenLabel = computed(() => (
+  isPull.value
+    ? t('storage.backup.siteSyncSourceToken')
+    : t('storage.backup.siteSyncToken')
+))
+const tokenPlaceholder = computed(() => (
+  isPull.value
+    ? t('storage.backup.siteSyncSourceTokenPlaceholder')
+    : t('storage.backup.siteSyncTokenPlaceholder')
+))
+const startLabel = computed(() => (
+  isPull.value
+    ? t('storage.backup.siteSyncStartPull')
+    : t('storage.backup.siteSyncStartPush')
+))
+
+function submit(resume = false) {
+  if (resume ? !canResume.value : !canSubmit.value) return
+  emit('sync', {
+    targetBaseUrl: targetBaseUrl.value.trim(),
+    token: token.value.trim(),
+    conflictMode: conflictMode.value,
+    direction: direction.value,
+    ...(resume && props.resumableJob ? { resumeJobId: props.resumableJob.id } : {})
+  })
+  token.value = ''
+}
+
+function startNew() {
+  submit(false)
+}
+
+function resumeSync() {
+  submit(true)
+}
+
+function setConflictMode(mode: 'skip' | 'overwrite') {
+  conflictMode.value = mode
+}
+
+function setDirection(value: SiteSyncDirection) {
+  direction.value = value
+}
+</script>
+
+<template>
+  <article class="rounded-xl border border-default bg-elevated p-4 sm:p-5">
+    <div class="flex items-start gap-3">
+      <div class="flex size-10 shrink-0 items-center justify-center rounded-lg bg-primary/10 text-primary">
+        <UIcon
+          name="i-lucide-server-cog"
+          class="size-5"
+        />
+      </div>
+      <div class="min-w-0">
+        <h3 class="text-base font-semibold">
+          {{ t('storage.backup.siteSyncTitle') }}
+        </h3>
+        <p class="mt-0.5 text-sm leading-relaxed text-muted">
+          {{ directionSubtitle }}
+        </p>
+      </div>
+    </div>
+
+    <div class="mt-4 grid gap-3 lg:grid-cols-[minmax(0,1.2fr)_minmax(0,1fr)_auto] lg:items-end">
+      <div class="space-y-1.5">
+        <label class="text-xs text-muted">{{ endpointLabel }}</label>
+        <UInput
+          v-model="targetBaseUrl"
+          placeholder="https://target.example.com"
+          size="sm"
+          class="w-full"
+          :disabled="busy || disabled"
+        />
+      </div>
+      <div class="space-y-1.5">
+        <label class="text-xs text-muted">{{ tokenLabel }}</label>
+        <UInput
+          v-model="token"
+          type="password"
+          :placeholder="tokenPlaceholder"
+          size="sm"
+          class="w-full"
+          :disabled="busy || disabled"
+        />
+      </div>
+      <UButton
+        :label="startLabel"
+        :icon="isPull ? 'i-lucide-cloud-download' : 'i-lucide-cloud-upload'"
+        color="primary"
+        :loading="busy"
+        :disabled="!canSubmit"
+        @click="startNew"
+      />
+      <UButton
+        v-if="resumableJob"
+        :label="t('storage.backup.siteSyncResume')"
+        icon="i-lucide-play"
+        color="warning"
+        :loading="busy"
+        :disabled="!canResume"
+        class="lg:col-start-3"
+        @click="resumeSync"
+      />
+    </div>
+
+    <div class="mt-3 grid gap-3 sm:grid-cols-2">
+      <div class="flex flex-wrap items-center gap-2">
+        <span class="text-xs text-muted">{{ t('storage.backup.siteSyncDirection') }}</span>
+        <UButton
+          size="xs"
+          :variant="direction === 'push' ? 'solid' : 'ghost'"
+          :color="direction === 'push' ? 'primary' : 'neutral'"
+          :label="t('storage.backup.siteSyncPush')"
+          :disabled="busy || disabled"
+          @click="setDirection('push')"
+        />
+        <UButton
+          size="xs"
+          :variant="direction === 'pull' ? 'solid' : 'ghost'"
+          :color="direction === 'pull' ? 'primary' : 'neutral'"
+          :label="t('storage.backup.siteSyncPull')"
+          :disabled="busy || disabled"
+          @click="setDirection('pull')"
+        />
+      </div>
+      <div class="flex flex-wrap items-center gap-2 sm:justify-end">
+        <span class="text-xs text-muted">{{ t('storage.backup.siteSyncConflict') }}</span>
+        <UButton
+          size="xs"
+          :variant="conflictMode === 'skip' ? 'solid' : 'ghost'"
+          :color="conflictMode === 'skip' ? 'primary' : 'neutral'"
+          :label="t('storage.backup.siteSyncSkip')"
+          :disabled="busy || disabled"
+          @click="setConflictMode('skip')"
+        />
+        <UButton
+          size="xs"
+          :variant="conflictMode === 'overwrite' ? 'solid' : 'ghost'"
+          :color="conflictMode === 'overwrite' ? 'primary' : 'neutral'"
+          :label="t('storage.backup.siteSyncOverwrite')"
+          :disabled="busy || disabled"
+          @click="setConflictMode('overwrite')"
+        />
+      </div>
+    </div>
+
+    <UAlert
+      v-if="activeJob"
+      class="mt-4"
+      color="primary"
+      variant="subtle"
+      icon="i-lucide-refresh-cw"
+      :description="activeJob.message"
+    />
+
+    <div
+      v-if="activeJob"
+      class="mt-3 grid gap-3 rounded-lg border border-default bg-default/40 p-3 sm:grid-cols-2"
+    >
+      <div>
+        <p class="text-xs text-muted">
+          {{ t('storage.backup.siteSyncScanProgress') }}
+        </p>
+        <p class="mt-1 font-mono text-sm font-medium">
+          {{ activeJob.message }}
+        </p>
+      </div>
+      <div>
+        <p class="text-xs text-muted">
+          {{ t('storage.backup.siteSyncFileProgress') }}
+        </p>
+        <p class="mt-1 font-mono text-sm font-medium">
+          {{ fileProgress.synced }} / {{ fileProgress.total }}
+        </p>
+      </div>
+    </div>
+
+    <BackupJobProgress
+      v-if="activeJob"
+      class="mt-2"
+      :message="activeJob.message"
+      :progress="activeJob.progress"
+      :total="activeJob.total"
+    />
+  </article>
+</template>
diff --git a/app/components/storage/StorageBackupPanel.vue b/app/components/storage/StorageBackupPanel.vue
index 30ccfa4..f291399 100644
--- a/app/components/storage/StorageBackupPanel.vue
+++ b/app/components/storage/StorageBackupPanel.vue
@@ -1,5 +1,9 @@
 <script setup lang="ts">
-import type { BackupJobItem, SyncDraft } from '~/types/backup'
+import type {
+  BackupJobItem,
+  SiteSyncRequest,
+  SyncDraft
+} from '~/types/backup'
 import type { StorageBackendItem } from '~/types/storage'
 
 const props = defineProps<{
@@ -31,6 +35,7 @@ const {
   confirmRestore,
   previewSync,
   startSync,
+  startSiteSync,
   retryJob,
   cancelJob,
   downloadUrl
@@ -45,6 +50,14 @@ const activeJob = computed(() => getActiveJob())
 const exportBusy = computed(() => activeJob.value?.type === 'full_export')
 const restoreBusy = computed(() => activeJob.value?.type === 'full_restore')
 const syncBusy = computed(() => activeJob.value?.type === 'backend_sync')
+const siteSyncBusy = computed(() => activeJob.value?.type === 'site_sync')
+const resumableSiteSyncJob = computed(() =>
+  jobs.value.find(job =>
+    job.type === 'site_sync'
+    && job.status === 'failed'
+    && job.payload.resumable === true
+  ) ?? null
+)
 const anyJobBusy = computed(() => Boolean(activeJob.value))
 
 onMounted(async () => {
@@ -94,6 +107,10 @@ async function onSync(body: {
   await startSync(body)
 }
 
+async function onSiteSync(body: SiteSyncRequest) {
+  await startSiteSync(body)
+}
+
 function onDownload(jobId: string) {
   window.open(downloadUrl(jobId), '_blank')
 }
@@ -159,6 +176,14 @@ function onViewJob(job: BackupJobItem) {
       />
     </div>
 
+    <StorageSiteSyncCard
+      :busy="siteSyncBusy"
+      :disabled="anyJobBusy && !siteSyncBusy"
+      :active-job="siteSyncBusy ? activeJob : null"
+      :resumable-job="resumableSiteSyncJob"
+      @sync="onSiteSync"
+    />
+
     <StorageBackupJobTable
       :jobs="jobs"
       :polling="polling"
diff --git a/app/composables/useBackup.ts b/app/composables/useBackup.ts
index 2084684..3ec3788 100644
--- a/app/composables/useBackup.ts
+++ b/app/composables/useBackup.ts
@@ -3,7 +3,8 @@ import type {
   BackupJobItem,
   BackupPackageItem,
   BackupRestorePreview,
-  BackendSyncPreview
+  BackendSyncPreview,
+  SiteSyncRequest
 } from '~/types/backup'
 
 const jobs = ref<BackupJobItem[]>([])
@@ -255,6 +256,26 @@ export function useBackup() {
     }
   }
 
+  async function startSiteSync(body: SiteSyncRequest) {
+    try {
+      const data = await $fetch<{ job: BackupJobItem }>(
+        '/api/admin/site-sync',
+        {
+          method: 'POST',
+          credentials: 'include',
+          body
+        }
+      )
+      await refreshJobsFirstPage()
+      startPolling()
+      toast.add({ title: t('storage.backup.siteSyncStarted'), color: 'success' })
+      return data.job
+    } catch (error: unknown) {
+      handleError(error, t('storage.backup.siteSyncFailed'))
+      throw error
+    }
+  }
+
   async function retryJob(jobId: string) {
     try {
       await $fetch(`/api/admin/backup/jobs/${jobId}/retry`, {
@@ -312,6 +333,7 @@ export function useBackup() {
     confirmRestore,
     previewSync,
     startSync,
+    startSiteSync,
     retryJob,
     cancelJob,
     downloadUrl
diff --git a/app/types/backup.ts b/app/types/backup.ts
index 8519127..2ac71b6 100644
--- a/app/types/backup.ts
+++ b/app/types/backup.ts
@@ -1,5 +1,6 @@
-export type BackupJobType = 'full_export' | 'full_restore' | 'backend_sync'
+export type BackupJobType = 'full_export' | 'full_restore' | 'backend_sync' | 'site_sync'
 export type BackupJobStatus = 'pending' | 'running' | 'done' | 'failed'
+export type SiteSyncDirection = 'push' | 'pull'
 
 export interface BackupJobItem {
   id: string
@@ -51,3 +52,11 @@ export interface SyncDraft {
   fromBackendId: string
   toBackendId: string
 }
+
+export interface SiteSyncRequest {
+  targetBaseUrl: string
+  token: string
+  conflictMode: 'skip' | 'overwrite'
+  direction: SiteSyncDirection
+  resumeJobId?: string
+}
diff --git a/i18n/locales/en.json b/i18n/locales/en.json
index c78a9d7..761d4ff 100644
--- a/i18n/locales/en.json
+++ b/i18n/locales/en.json
@@ -645,6 +645,30 @@
       "conflictSkip": "Skip existing files",
       "conflictOverwrite": "Overwrite existing files and database",
       "syncTitle": "Cross-backend sync",
+      "siteSyncTitle": "Site-to-site sync",
+      "siteSyncSubtitle": "Sync media indexes, images, videos, files, thumbnails, HLS segments and tags to another PicHost. Matching usernames must already exist on the target.",
+      "siteSyncPushSubtitle": "Push media indexes, images, videos, files, thumbnails, HLS segments and tags to another PicHost. Matching usernames must already exist on the target.",
+      "siteSyncPullSubtitle": "Pull media indexes, images, videos, files, thumbnails, HLS segments and tags from another PicHost. Matching usernames must already exist on this site.",
+      "siteSyncTarget": "Target site URL",
+      "siteSyncSource": "Source site URL",
+      "siteSyncToken": "Target admin API token",
+      "siteSyncSourceToken": "Source admin API token",
+      "siteSyncTokenPlaceholder": "Enter target admin token",
+      "siteSyncSourceTokenPlaceholder": "Enter source admin token",
+      "siteSyncStart": "Start sync",
+      "siteSyncStartPush": "Start push",
+      "siteSyncStartPull": "Start pull",
+      "siteSyncDirection": "Sync direction:",
+      "siteSyncPush": "Push to target",
+      "siteSyncPull": "Pull from target",
+      "siteSyncConflict": "Conflict policy:",
+      "siteSyncSkip": "Skip existing",
+      "siteSyncOverwrite": "Overwrite existing",
+      "siteSyncResume": "Resume last sync",
+      "siteSyncScanProgress": "Media scan progress",
+      "siteSyncFileProgress": "Synced file count",
+      "siteSyncStarted": "Site-to-site sync started",
+      "siteSyncFailed": "Failed to start site-to-site sync",
       "syncMigrateTitle": "Cross-backend migration",
       "syncMigrateSubtitle": "Migrate files between configured backends",
       "syncSubtitle": "Copy files between configured backends and update the index",
@@ -694,6 +718,7 @@
       "jobTypeExport": "Site export",
       "jobTypeRestore": "Site restore",
       "jobTypeSync": "Cross-backend sync",
+      "jobTypeSiteSync": "Site-to-site sync",
       "statusPending": "Pending",
       "statusRunning": "Running",
       "statusDone": "Done",
diff --git a/i18n/locales/zh-CN.json b/i18n/locales/zh-CN.json
index 7f6aefc..4cb395b 100644
--- a/i18n/locales/zh-CN.json
+++ b/i18n/locales/zh-CN.json
@@ -645,6 +645,30 @@
       "conflictSkip": "跳过已存在文件",
       "conflictOverwrite": "覆盖已存在文件与数据库",
       "syncTitle": "跨后端同步",
+      "siteSyncTitle": "两站点同步",
+      "siteSyncSubtitle": "将当前站点的媒体索引、图片、视频、文件、缩略图、HLS 分片和标签同步到另一台 PicHost。目标站点需已有同名用户。",
+      "siteSyncPushSubtitle": "将当前站点的媒体索引、图片、视频、文件、缩略图、HLS 分片和标签推送到另一台 PicHost。目标站点需已有同名用户。",
+      "siteSyncPullSubtitle": "从另一台 PicHost 拉取媒体索引、图片、视频、文件、缩略图、HLS 分片和标签。当前站点需已有同名用户。",
+      "siteSyncTarget": "目标站点地址",
+      "siteSyncSource": "来源站点地址",
+      "siteSyncToken": "目标站点管理员 API Token",
+      "siteSyncSourceToken": "来源站点管理员 API Token",
+      "siteSyncTokenPlaceholder": "输入目标站点管理员 Token",
+      "siteSyncSourceTokenPlaceholder": "输入来源站点管理员 Token",
+      "siteSyncStart": "开始同步",
+      "siteSyncStartPush": "开始推送",
+      "siteSyncStartPull": "开始拉取",
+      "siteSyncDirection": "同步策略：",
+      "siteSyncPush": "推送到目标站点",
+      "siteSyncPull": "从目标站点拉取",
+      "siteSyncConflict": "冲突策略：",
+      "siteSyncSkip": "跳过已存在",
+      "siteSyncOverwrite": "覆盖已存在",
+      "siteSyncResume": "继续上次同步",
+      "siteSyncScanProgress": "媒体扫描进度",
+      "siteSyncFileProgress": "已同步文件数量",
+      "siteSyncStarted": "两站点同步任务已开始",
+      "siteSyncFailed": "启动两站点同步失败",
       "syncMigrateTitle": "跨后端迁移",
       "syncMigrateSubtitle": "在已配置后端之间迁移文件",
       "syncSubtitle": "在已配置的后端之间拷贝文件并更新索引",
@@ -694,6 +718,7 @@
       "jobTypeExport": "站点导出",
       "jobTypeRestore": "站点恢复",
       "jobTypeSync": "跨后端同步",
+      "jobTypeSiteSync": "两站点同步",
       "statusPending": "等待中",
       "statusRunning": "进行中",
       "statusDone": "已完成",
diff --git a/server/api/admin/site-sync.post.ts b/server/api/admin/site-sync.post.ts
new file mode 100644
index 0000000..669ddf7
--- /dev/null
+++ b/server/api/admin/site-sync.post.ts
@@ -0,0 +1,59 @@
+import { requireAdminAuth } from '../../utils/access'
+import { createApiError } from '../../utils/api-error'
+import { serializeBackupJob } from '../../utils/backup/api'
+import {
+  resumeSiteSyncJob,
+  startSiteSyncJob
+} from '../../utils/backup/runner'
+
+interface SiteSyncBody {
+  targetBaseUrl?: string
+  token?: string
+  conflictMode?: 'skip' | 'overwrite'
+  direction?: 'push' | 'pull'
+  resumeJobId?: string
+}
+
+export default defineEventHandler(async (event) => {
+  const user = await requireAdminAuth(event)
+  const body = await readBody<SiteSyncBody>(event).catch(() => null)
+  const targetBaseUrl = body?.targetBaseUrl?.trim() ?? ''
+  const token = body?.token?.trim() ?? ''
+  const conflictMode = body?.conflictMode === 'skip' ? 'skip' : 'overwrite'
+  const direction = body?.direction === 'pull' ? 'pull' : 'push'
+
+  if (!token) {
+    createApiError(event, 'INVALID_REQUEST', '请输入目标站点管理员 API Token', 400)
+  }
+
+  try {
+    let job
+    if (body?.resumeJobId) {
+      job = resumeSiteSyncJob(body.resumeJobId, token, user.id)
+    } else {
+      let targetUrl: URL
+      try {
+        targetUrl = new URL(targetBaseUrl)
+        if (targetUrl.protocol !== 'http:' && targetUrl.protocol !== 'https:') {
+          throw new Error('invalid protocol')
+        }
+      } catch {
+        createApiError(event, 'INVALID_REQUEST', '请输入有效的目标站点地址', 400)
+      }
+      job = startSiteSyncJob({
+        targetBaseUrl: targetUrl.toString(),
+        conflictMode,
+        direction
+      }, token, user.id)
+    }
+    return { job: serializeBackupJob(job) }
+  } catch (error) {
+    if (error instanceof Error && error.message === 'BACKUP_JOB_RUNNING') {
+      createApiError(event, 'CONFLICT', '已有备份或迁移任务正在运行', 409)
+    }
+    if (error instanceof Error && error.message === 'SITE_SYNC_JOB_NOT_RESUMABLE') {
+      createApiError(event, 'INVALID_REQUEST', '该同步任务无法继续', 400)
+    }
+    throw error
+  }
+})
diff --git a/server/api/files/batch-delete.post.ts b/server/api/files/batch-delete.post.ts
index e430719..fa14fb2 100644
--- a/server/api/files/batch-delete.post.ts
+++ b/server/api/files/batch-delete.post.ts
@@ -3,7 +3,7 @@ import { assertImageOwnership, requireApiOrAdminAuth } from '../../utils/access'
 import { createApiError } from '../../utils/api-error'
 import { logActivity } from '../../utils/activity-log'
 import { deleteImageIndex, getImageIndexRow } from '../../utils/image-index'
-import { validateFileKey, validateVideoKey } from '../../utils/image-key'
+import { validateStorageKey, validateVideoKey } from '../../utils/image-key'
 import { deleteImage, headImage } from '../../utils/storage'
 import { cancelTranscode, removeHlsArtifacts } from '../../utils/transcode'
 import { MAX_DELETE_BATCH } from '../../utils/constants'
@@ -31,7 +31,7 @@ export default defineEventHandler(async (event) => {
   const failed: BatchDeleteResponse['failed'] = []
 
   for (const key of keys) {
-    if (!validateFileKey(key) && !validateVideoKey(key)) {
+    if (!validateStorageKey(key)) {
       failed.push({ key, error: { code: 'INVALID_IMAGE_KEY', message: '无效的文件路径' } })
       continue
     }
diff --git a/server/api/files/index.delete.ts b/server/api/files/index.delete.ts
index 96c5bee..483bbca 100644
--- a/server/api/files/index.delete.ts
+++ b/server/api/files/index.delete.ts
@@ -3,7 +3,7 @@ import { assertImageOwnership, requireApiOrAdminAuth } from '../../utils/access'
 import { createApiError } from '../../utils/api-error'
 import { logActivity } from '../../utils/activity-log'
 import { deleteImageIndex, getImageIndexRow } from '../../utils/image-index'
-import { validateFileKey, validateVideoKey } from '../../utils/image-key'
+import { validateStorageKey, validateVideoKey } from '../../utils/image-key'
 import { deleteImage, headImage } from '../../utils/storage'
 import { cancelTranscode, removeHlsArtifacts } from '../../utils/transcode'
 import { logInfo } from '../../utils/logger'
@@ -20,7 +20,7 @@ export default defineEventHandler(async (event) => {
     const body = await readBody<DeleteBody>(event).catch(() => null)
     const key = (typeof query.key === 'string' ? query.key : undefined) ?? body?.key
 
-    if (!key || (!validateFileKey(key) && !validateVideoKey(key))) {
+    if (!key || !validateStorageKey(key)) {
       createApiError(event, 'INVALID_IMAGE_KEY', '无效的文件路径', 400)
     }
 
diff --git a/server/api/site-sync/inventory.get.ts b/server/api/site-sync/inventory.get.ts
new file mode 100644
index 0000000..ef064d7
--- /dev/null
+++ b/server/api/site-sync/inventory.get.ts
@@ -0,0 +1,38 @@
+import { requireSiteSyncAuth } from '../../utils/access'
+import { listAllImageIndexRows } from '../../utils/image-index'
+import { listUserIdUsernameMap } from '../../utils/db'
+import { collectMediaAssetKeys } from '../../utils/media-assets'
+import { getBackendForKey } from '../../utils/storage/resolver'
+import type { SiteSyncInventory } from '../../utils/site-sync/protocol'
+
+export default defineEventHandler(async (event): Promise<SiteSyncInventory> => {
+  await requireSiteSyncAuth(event)
+
+  const rows = listAllImageIndexRows()
+  const objects = new Map<string, number>()
+
+  for (const row of rows) {
+    const backend = await getBackendForKey(row.key)
+    let keys: string[]
+    try {
+      keys = await collectMediaAssetKeys(row, backend)
+    } catch {
+      keys = [
+        ...(Number(row.source_deleted ?? 0) !== 1 ? [row.key] : []),
+        ...(row.thumb_key ? [row.thumb_key] : []),
+        ...(row.hls_key ? [row.hls_key] : [])
+      ]
+    }
+
+    for (const key of new Set(keys)) {
+      const stored = await backend.head(key)
+      if (stored) objects.set(key, stored.size)
+    }
+  }
+
+  return {
+    users: [...listUserIdUsernameMap().values()].sort(),
+    mediaKeys: rows.map(row => row.key),
+    objects: [...objects].map(([key, size]) => ({ key, size }))
+  }
+})
diff --git a/server/api/site-sync/media.get.ts b/server/api/site-sync/media.get.ts
new file mode 100644
index 0000000..90d8a8e
--- /dev/null
+++ b/server/api/site-sync/media.get.ts
@@ -0,0 +1,75 @@
+import { getQuery } from 'h3'
+import { requireSiteSyncAuth } from '../../utils/access'
+import { createApiError } from '../../utils/api-error'
+import { listUserIdUsernameMap } from '../../utils/db'
+import {
+  getImageIndexRow,
+  getImageTotals,
+  listImageIndexRowsAfter
+} from '../../utils/image-index'
+import { validateStorageKey } from '../../utils/image-key'
+import { collectMediaAssetKeys } from '../../utils/media-assets'
+import { getBackendForKey } from '../../utils/storage/resolver'
+import { getTagsForImageKeys } from '../../utils/tags'
+import { toSiteSyncMediaTransfer } from '../../utils/site-sync/manifest'
+import type {
+  SiteSyncMediaAsset,
+  SiteSyncMediaBundle,
+  SiteSyncMediaPage
+} from '../../utils/site-sync/protocol'
+
+export default defineEventHandler(async (event): Promise<SiteSyncMediaPage> => {
+  await requireSiteSyncAuth(event)
+
+  const query = getQuery(event)
+  const key = typeof query.key === 'string' ? query.key.trim() : ''
+  const after = typeof query.after === 'string' ? query.after : ''
+  const limit = Math.min(
+    100,
+    Math.max(1, Number.parseInt(String(query.limit ?? '50'), 10) || 50)
+  )
+
+  if (key && !validateStorageKey(key)) {
+    createApiError(event, 'INVALID_REQUEST', '媒体 key 无效', 400)
+  }
+
+  const rows = key
+    ? [getImageIndexRow(key)].filter(row => row !== null)
+    : listImageIndexRowsAfter(after, limit)
+  if (key && rows.length === 0) {
+    createApiError(event, 'IMAGE_NOT_FOUND', '目标媒体不存在', 404)
+  }
+
+  const ownerMap = listUserIdUsernameMap()
+  const tagMap = getTagsForImageKeys(rows.map(row => row.key))
+  const items: SiteSyncMediaBundle[] = []
+
+  for (const row of rows) {
+    const backend = await getBackendForKey(row.key)
+    const keys = await collectMediaAssetKeys(row, backend)
+    const assets: SiteSyncMediaAsset[] = []
+    for (const assetKey of new Set(keys)) {
+      const stored = await backend.head(assetKey)
+      if (!stored) {
+        throw new Error(`目标媒体对象不存在：${assetKey}`)
+      }
+      assets.push({ key: assetKey, size: stored.size })
+    }
+    items.push({
+      media: toSiteSyncMediaTransfer(
+        row,
+        row.user_id == null ? null : ownerMap.get(row.user_id) ?? null,
+        tagMap.get(row.key) ?? []
+      ),
+      assets
+    })
+  }
+
+  return {
+    items,
+    totalMedia: getImageTotals().count,
+    nextCursor: key || rows.length < limit
+      ? null
+      : rows.at(-1)?.key ?? null
+  }
+})
diff --git a/server/api/site-sync/media.post.ts b/server/api/site-sync/media.post.ts
new file mode 100644
index 0000000..6f5a115
--- /dev/null
+++ b/server/api/site-sync/media.post.ts
@@ -0,0 +1,26 @@
+import { requireSiteSyncAuth } from '../../utils/access'
+import { createApiError } from '../../utils/api-error'
+import { validateStorageKey } from '../../utils/image-key'
+import { applySiteSyncMedia } from '../../utils/site-sync/apply'
+import type { SiteSyncMediaTransfer } from '../../utils/site-sync/protocol'
+
+interface Body {
+  media?: SiteSyncMediaTransfer
+  conflictMode?: 'skip' | 'overwrite'
+}
+
+export default defineEventHandler(async (event) => {
+  const admin = await requireSiteSyncAuth(event)
+  const body = await readBody<Body>(event).catch(() => null)
+  const media = body?.media
+  if (!media || !validateStorageKey(media.key)) {
+    createApiError(event, 'INVALID_REQUEST', '媒体同步参数无效', 400)
+  }
+  const conflictMode = body?.conflictMode === 'skip' ? 'skip' : 'overwrite'
+  try {
+    return await applySiteSyncMedia(media, conflictMode, admin.id)
+  } catch (error) {
+    const message = error instanceof Error ? error.message : '媒体同步失败'
+    createApiError(event, 'INVALID_REQUEST', message, 400)
+  }
+})
diff --git a/server/api/site-sync/object.get.ts b/server/api/site-sync/object.get.ts
new file mode 100644
index 0000000..8bc694b
--- /dev/null
+++ b/server/api/site-sync/object.get.ts
@@ -0,0 +1,26 @@
+import { getQuery, sendStream, setResponseHeader } from 'h3'
+import { requireSiteSyncAuth } from '../../utils/access'
+import { createApiError } from '../../utils/api-error'
+import { validateStorageKey } from '../../utils/image-key'
+import { getBackendForKey } from '../../utils/storage/resolver'
+
+export default defineEventHandler(async (event) => {
+  await requireSiteSyncAuth(event)
+
+  const query = getQuery(event)
+  const key = typeof query.key === 'string' ? query.key.trim() : ''
+  if (!validateStorageKey(key)) {
+    createApiError(event, 'INVALID_REQUEST', '同步对象 key 无效', 400)
+  }
+
+  const backend = await getBackendForKey(key)
+  const stored = await backend.head(key)
+  if (!stored) {
+    createApiError(event, 'IMAGE_NOT_FOUND', `目标对象不存在：${key}`, 404)
+  }
+
+  setResponseHeader(event, 'Content-Type', stored.contentType)
+  setResponseHeader(event, 'Content-Length', stored.size)
+  setResponseHeader(event, 'Cache-Control', 'no-store')
+  return sendStream(event, await backend.createStream(key))
+})
diff --git a/server/api/site-sync/object.post.ts b/server/api/site-sync/object.post.ts
new file mode 100644
index 0000000..f386d3d
--- /dev/null
+++ b/server/api/site-sync/object.post.ts
@@ -0,0 +1,54 @@
+import { readMultipartFormData } from 'h3'
+import { requireSiteSyncAuth } from '../../utils/access'
+import { createApiError } from '../../utils/api-error'
+import { MAX_VIDEO_FILE_SIZE } from '../../utils/constants'
+import { findUserByUsername } from '../../utils/db'
+import { validateStorageKey } from '../../utils/image-key'
+import { getActiveBackend } from '../../utils/storage/resolver'
+
+function field(form: Awaited<ReturnType<typeof readMultipartFormData>>, name: string): string {
+  const part = form?.find(item => item.name === name)
+  return part?.data?.length ? new TextDecoder().decode(part.data).trim() : ''
+}
+
+export default defineEventHandler(async (event) => {
+  await requireSiteSyncAuth(event)
+  const form = await readMultipartFormData(event)
+  if (!form?.length) createApiError(event, 'INVALID_REQUEST', '未收到同步数据', 400)
+
+  const key = field(form, 'key')
+  const file = form.find(part => part.name === 'file' && part.data?.length)
+  if (!validateStorageKey(key) || !file?.data) {
+    createApiError(event, 'INVALID_REQUEST', '同步文件参数无效', 400)
+  }
+  if (file.data.length > MAX_VIDEO_FILE_SIZE) {
+    createApiError(event, 'FILE_TOO_LARGE', '同步文件超过 500 MB', 413)
+  }
+
+  const conflictMode = field(form, 'conflictMode') === 'skip' ? 'skip' : 'overwrite'
+  const backend = await getActiveBackend()
+  if (conflictMode === 'skip' && await backend.head(key)) {
+    return { success: true, skipped: true }
+  }
+
+  const ownerUsername = field(form, 'ownerUsername')
+  const owner = ownerUsername ? findUserByUsername(ownerUsername) : null
+  if (ownerUsername && !owner) {
+    createApiError(event, 'INVALID_REQUEST', `目标站点缺少用户：${ownerUsername}`, 400)
+  }
+
+  await backend.put(key, new Uint8Array(file.data), {
+    originalName: field(form, 'originalName') || file.filename || key.split('/').pop() || 'file',
+    uploadedAt: field(form, 'uploadedAt') || new Date().toISOString(),
+    contentType: file.type || field(form, 'contentType') || 'application/octet-stream',
+    size: file.data.length,
+    userId: owner?.id ?? null,
+    mediaType: key.startsWith('videos/')
+      ? 'video'
+      : key.startsWith('files/')
+        ? 'file'
+        : 'image'
+  })
+
+  return { success: true, skipped: false }
+})
diff --git a/server/api/site-sync/users.get.ts b/server/api/site-sync/users.get.ts
new file mode 100644
index 0000000..4537d87
--- /dev/null
+++ b/server/api/site-sync/users.get.ts
@@ -0,0 +1,10 @@
+import { requireSiteSyncAuth } from '../../utils/access'
+import { listUserIdUsernameMap } from '../../utils/db'
+import type { SiteSyncUsers } from '../../utils/site-sync/protocol'
+
+export default defineEventHandler(async (event): Promise<SiteSyncUsers> => {
+  await requireSiteSyncAuth(event)
+  return {
+    users: [...listUserIdUsernameMap().values()].sort()
+  }
+})
diff --git a/server/utils/access.ts b/server/utils/access.ts
index b5ec016..90e190e 100644
--- a/server/utils/access.ts
+++ b/server/utils/access.ts
@@ -1,5 +1,5 @@
 import type { H3Event } from 'h3'
-import { findUserByApiToken, getPrimaryAdminUserId } from './db'
+import { findUserById, findUserByApiToken, getPrimaryAdminUserId } from './db'
 import { getAdminSecret, getApiUploadToken } from './env'
 import { createApiError } from './api-error'
 import {
@@ -110,6 +110,36 @@ export function resolveUserIdFromApiToken(
   return null
 }
 
+/** 两站点同步：全站 Token 或管理员个人 Token；也允许管理员网页会话。 */
+export async function requireSiteSyncAuth(event: H3Event): Promise<AuthUser> {
+  if (devBypass(event)) {
+    return { id: 0, username: 'dev', role: 'admin' }
+  }
+
+  if (verifyGlobalApiUploadToken(event)) {
+    const adminId = getPrimaryAdminUserId()
+    if (adminId != null) {
+      const admin = findUserById(adminId)
+      if (admin) {
+        return { id: admin.id, username: admin.username, role: admin.role }
+      }
+    }
+  }
+
+  const userId = resolveUserIdFromApiToken(event)
+  if (userId != null) {
+    const user = findUserById(userId)
+    if (user?.role === 'admin') {
+      return { id: user.id, username: user.username, role: user.role }
+    }
+  }
+
+  const sessionUser = await getCurrentUser(event)
+  if (sessionUser?.role === 'admin') return sessionUser
+
+  createApiError(event, 'FORBIDDEN', '需要目标站点管理员同步 Token', 403)
+}
+
 export function verifyApiUploadToken(event: H3Event): boolean {
   return verifyGlobalApiUploadToken(event)
     || resolveUserIdFromApiToken(event) !== null
diff --git a/server/utils/backup/index.ts b/server/utils/backup/index.ts
index 51a545e..e7e744f 100644
--- a/server/utils/backup/index.ts
+++ b/server/utils/backup/index.ts
@@ -9,6 +9,8 @@ export {
   startFullExportJob,
   startFullRestoreJob,
   startBackendSyncJob,
+  startSiteSyncJob,
+  resumeSiteSyncJob,
   isBackupRunnerBusy,
   cancelBackupJob
 } from './runner'
diff --git a/server/utils/backup/jobs.ts b/server/utils/backup/jobs.ts
index 104661a..941bf8e 100644
--- a/server/utils/backup/jobs.ts
+++ b/server/utils/backup/jobs.ts
@@ -2,7 +2,7 @@ import { randomBytes } from 'node:crypto'
 import { getDb, getPrimaryAdminUserId } from '../db'
 import { ensureBackupSchema } from './schema'
 
-export type BackupJobType = 'full_export' | 'full_restore' | 'backend_sync'
+export type BackupJobType = 'full_export' | 'full_restore' | 'backend_sync' | 'site_sync'
 export type BackupJobStatus = 'pending' | 'running' | 'done' | 'failed'
 
 export interface BackupJob {
diff --git a/server/utils/backup/runner.ts b/server/utils/backup/runner.ts
index 6df0ec6..82573ae 100644
--- a/server/utils/backup/runner.ts
+++ b/server/utils/backup/runner.ts
@@ -1,6 +1,7 @@
 import { runBackendSyncJob } from './backend-sync'
 import { runFullExportJob } from './full-export'
 import { runFullRestoreJob } from './full-restore'
+import { registerSiteSyncToken, runSiteSyncJob, type SiteSyncOptions } from '../site-sync/runner'
 import {
   createBackupJob,
   getBackupJob,
@@ -114,3 +115,55 @@ export function startBackendSyncJob(options: {
   scheduleBackupJob(job, () => runBackendSyncJob(job.id, options))
   return getBackupJob(job.id)!
 }
+
+export function startSiteSyncJob(
+  options: SiteSyncOptions,
+  token: string,
+  userId?: number | null
+): BackupJob {
+  claimJobSlot()
+  const job = createBackupJob({
+    type: 'site_sync',
+    userId,
+    message: '等待开始…',
+    payload: {
+      targetBaseUrl: options.targetBaseUrl,
+      conflictMode: options.conflictMode,
+      direction: options.direction
+    }
+  })
+  registerSiteSyncToken(job.id, token)
+  scheduleBackupJob(job, () => runSiteSyncJob(job.id, options))
+  return getBackupJob(job.id)!
+}
+
+export function resumeSiteSyncJob(
+  jobId: string,
+  token: string,
+  userId?: number | null
+): BackupJob {
+  claimJobSlot()
+  const job = getBackupJob(jobId, userId ?? undefined)
+  if (
+    !job
+    || job.type !== 'site_sync'
+    || job.status !== 'failed'
+    || job.payload.resumable !== true
+  ) {
+    throw new Error('SITE_SYNC_JOB_NOT_RESUMABLE')
+  }
+  const targetBaseUrl = typeof job.payload.targetBaseUrl === 'string'
+    ? job.payload.targetBaseUrl
+    : ''
+  const conflictMode = job.payload.conflictMode === 'skip' ? 'skip' : 'overwrite'
+  const direction = job.payload.direction === 'pull' ? 'pull' : 'push'
+  if (!targetBaseUrl) throw new Error('SITE_SYNC_JOB_NOT_RESUMABLE')
+
+  registerSiteSyncToken(job.id, token)
+  scheduleBackupJob(job, () => runSiteSyncJob(job.id, {
+    targetBaseUrl,
+    conflictMode,
+    direction
+  }))
+  return getBackupJob(job.id)!
+}
diff --git a/server/utils/backup/schema.ts b/server/utils/backup/schema.ts
index 2cff10c..3c50812 100644
--- a/server/utils/backup/schema.ts
+++ b/server/utils/backup/schema.ts
@@ -1,11 +1,50 @@
 import { getDb } from '../db'
 
+function backupJobsTableSql(): string {
+  const row = getDb().prepare(`
+    SELECT sql FROM sqlite_master WHERE type = 'table' AND name = 'backup_jobs'
+  `).get() as { sql?: string } | undefined
+  return row?.sql ?? ''
+}
+
+function migrateBackupJobTypes(): void {
+  if (backupJobsTableSql().includes('\'site_sync\'')) return
+
+  const db = getDb()
+  db.exec(`
+    CREATE TABLE backup_jobs_new (
+      id TEXT PRIMARY KEY,
+      user_id INTEGER,
+      type TEXT NOT NULL CHECK(type IN ('full_export', 'full_restore', 'backend_sync', 'site_sync')),
+      status TEXT NOT NULL CHECK(status IN ('pending', 'running', 'done', 'failed')),
+      progress INTEGER NOT NULL DEFAULT 0,
+      total INTEGER NOT NULL DEFAULT 0,
+      message TEXT NOT NULL DEFAULT '',
+      payload_json TEXT NOT NULL DEFAULT '{}',
+      output_path TEXT,
+      error TEXT,
+      created_at TEXT NOT NULL,
+      finished_at TEXT
+    );
+    INSERT INTO backup_jobs_new
+      (id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, finished_at)
+    SELECT id, user_id, type, status, progress, total, message, payload_json, output_path, error, created_at, finished_at
+    FROM backup_jobs;
+    DROP TABLE backup_jobs;
+    ALTER TABLE backup_jobs_new RENAME TO backup_jobs;
+    CREATE INDEX IF NOT EXISTS idx_backup_jobs_created_at
+      ON backup_jobs(created_at DESC);
+    CREATE INDEX IF NOT EXISTS idx_backup_jobs_user_created
+      ON backup_jobs(user_id, created_at DESC);
+  `)
+}
+
 export function ensureBackupSchema(): void {
   getDb().exec(`
     CREATE TABLE IF NOT EXISTS backup_jobs (
       id TEXT PRIMARY KEY,
       user_id INTEGER,
-      type TEXT NOT NULL CHECK(type IN ('full_export', 'full_restore', 'backend_sync')),
+      type TEXT NOT NULL CHECK(type IN ('full_export', 'full_restore', 'backend_sync', 'site_sync')),
       status TEXT NOT NULL CHECK(status IN ('pending', 'running', 'done', 'failed')),
       progress INTEGER NOT NULL DEFAULT 0,
       total INTEGER NOT NULL DEFAULT 0,
@@ -36,4 +75,5 @@ export function ensureBackupSchema(): void {
     WHERE user_id IS NULL
       AND EXISTS (SELECT 1 FROM users WHERE role = 'admin');
   `)
+  migrateBackupJobTypes()
 }
diff --git a/server/utils/image-index.ts b/server/utils/image-index.ts
index 413a3ac..f5af036 100644
--- a/server/utils/image-index.ts
+++ b/server/utils/image-index.ts
@@ -35,6 +35,7 @@ export interface ImageIndexRow {
   backend_id: string
   user_id: number | null
   folder: string
+  media_type: MediaType
   original_name: string
   content_type: string
   size: number
@@ -71,6 +72,7 @@ function rowToStoredImage(row: ImageIndexRow): StoredImage {
     contentType: row.content_type,
     size: row.size,
     userId: row.user_id,
+    mediaType: row.media_type,
     hlsKey: row.hls_key ?? null,
     transcodeStatus: (row.transcode_status ?? 'none') as TranscodeStatus,
     transcodeProgress: Number(row.transcode_progress ?? 0),
@@ -232,7 +234,7 @@ export async function purgeOrphanImageIndexRows(): Promise<number> {
 export function getImageIndexRow(key: string): ImageIndexRow | null {
   ensureStorageSchema()
   const row = getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     WHERE key = ?
   `).get(key) as ImageIndexRow | undefined
@@ -425,16 +427,30 @@ export function getImageTotals(): { count: number, bytes: number } {
 export function listAllImageIndexRows(): ImageIndexRow[] {
   ensureStorageSchema()
   return getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     ORDER BY key ASC
   `).all() as unknown as ImageIndexRow[]
 }
 
+export function listImageIndexRowsAfter(
+  afterKey: string,
+  limit: number
+): ImageIndexRow[] {
+  ensureStorageSchema()
+  return getDb().prepare(`
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    FROM images
+    WHERE key > ?
+    ORDER BY key ASC
+    LIMIT ?
+  `).all(afterKey, limit) as unknown as ImageIndexRow[]
+}
+
 export function listImageIndexRowsForUser(userId: number): ImageIndexRow[] {
   ensureStorageSchema()
   return getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     WHERE user_id = ?
     ORDER BY key ASC
@@ -444,7 +460,7 @@ export function listImageIndexRowsForUser(userId: number): ImageIndexRow[] {
 export function listImageIndexRowsByBackend(backendId: string): ImageIndexRow[] {
   ensureStorageSchema()
   return getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     WHERE backend_id = ?
     ORDER BY key ASC
@@ -687,7 +703,7 @@ export async function listImages(options: {
   const backendSql = buildBackendFilterSql(options.backendId, params)
   const tagSql = buildTagFilterSql(options.tagFilter, params)
   const rows = getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     WHERE ${clauses.join(' AND ')}${userSql}${backendSql}${tagSql}
     ORDER BY uploaded_at DESC, key DESC
@@ -733,7 +749,7 @@ export async function searchImages(options: {
   const backendSql = buildBackendFilterSql(options.backendId, params)
   const tagSql = buildTagFilterSql(options.tagFilter, params)
   const rows = getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     WHERE ${clauses.join(' AND ')}${userSql}${backendSql}${tagSql}
     ORDER BY uploaded_at DESC, key DESC
@@ -867,7 +883,7 @@ export async function getUserScopedStorageStats(
 export async function listImageKeysForAutoDelete(): Promise<StoredImage[]> {
   ensureStorageSchema()
   const rows = getDb().prepare(`
-    SELECT key, backend_id, user_id, folder, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
+    SELECT key, backend_id, user_id, folder, media_type, original_name, content_type, size, uploaded_at, hls_key, transcode_status, transcode_progress, thumb_key, source_deleted, transcode_preset, transcode_error
     FROM images
     WHERE media_type = 'image'
     ORDER BY uploaded_at ASC
diff --git a/server/utils/media-assets.test.ts b/server/utils/media-assets.test.ts
index da47c9a..58614c3 100644
--- a/server/utils/media-assets.test.ts
+++ b/server/utils/media-assets.test.ts
@@ -8,6 +8,7 @@ const row: ImageIndexRow = {
   backend_id: 'local',
   user_id: 1,
   folder: 'videos',
+  media_type: 'video',
   original_name: 'example.mp4',
   content_type: 'video/mp4',
   size: 100,
diff --git a/server/utils/site-sync/apply.ts b/server/utils/site-sync/apply.ts
new file mode 100644
index 0000000..d9a811d
--- /dev/null
+++ b/server/utils/site-sync/apply.ts
@@ -0,0 +1,79 @@
+import { findUserByUsername } from '../db'
+import {
+  getImageIndexRow,
+  insertImageIndex,
+  updateImageThumb,
+  updateImageTranscode
+} from '../image-index'
+import { getActiveBackend } from '../storage/resolver'
+import {
+  createTag,
+  findTagByName,
+  setImageTags
+} from '../tags'
+import type { SiteSyncMediaTransfer } from './protocol'
+
+export async function applySiteSyncMedia(
+  media: SiteSyncMediaTransfer,
+  conflictMode: 'skip' | 'overwrite',
+  actorUserId: number
+): Promise<{ success: true, skipped: boolean }> {
+  if (conflictMode === 'skip' && getImageIndexRow(media.key)) {
+    return { success: true, skipped: true }
+  }
+
+  const owner = media.ownerUsername
+    ? findUserByUsername(media.ownerUsername)
+    : null
+  if (media.ownerUsername && !owner) {
+    throw new Error(`当前站点缺少用户：${media.ownerUsername}`)
+  }
+
+  const backend = await getActiveBackend()
+  const requiredKeys = [
+    ...(!media.sourceDeleted ? [media.key] : []),
+    ...(media.thumbKey ? [media.thumbKey] : []),
+    ...(media.hlsKey ? [media.hlsKey] : [])
+  ]
+  for (const key of requiredKeys) {
+    if (!await backend.head(key)) {
+      throw new Error(`同步对象尚未写入：${key}`)
+    }
+  }
+
+  insertImageIndex({
+    key: media.key,
+    backendId: backend.id,
+    userId: owner?.id ?? null,
+    originalName: media.originalName,
+    contentType: media.contentType,
+    size: media.size,
+    uploadedAt: media.uploadedAt,
+    mediaType: media.mediaType
+  })
+
+  if (media.thumbKey) updateImageThumb(media.key, media.thumbKey)
+  if (media.mediaType === 'video') {
+    updateImageTranscode(media.key, {
+      status: media.transcodeStatus,
+      hlsKey: media.hlsKey,
+      progress: media.transcodeProgress,
+      preset: media.transcodePreset,
+      sourceDeleted: media.sourceDeleted,
+      error: media.transcodeError
+    })
+  }
+
+  const tagOwnerId = owner?.id ?? actorUserId
+  const tagIds: number[] = []
+  for (const tag of media.tags) {
+    const existing = findTagByName(tagOwnerId, tag.name)
+    const item = existing
+      ? { id: existing.id }
+      : createTag(tagOwnerId, tag.name, tag.color)
+    tagIds.push(item.id)
+  }
+  setImageTags(media.key, tagIds, tagOwnerId, true)
+
+  return { success: true, skipped: false }
+}
diff --git a/server/utils/site-sync/manifest.ts b/server/utils/site-sync/manifest.ts
new file mode 100644
index 0000000..9972c91
--- /dev/null
+++ b/server/utils/site-sync/manifest.ts
@@ -0,0 +1,38 @@
+import type { ImageIndexRow } from '../image-index'
+import { getTagsForImageKeys } from '../tags'
+import type {
+  SiteSyncMediaTransfer,
+  SiteSyncTag
+} from './protocol'
+
+export function toSiteSyncMediaTransfer(
+  row: ImageIndexRow,
+  ownerUsername: string | null,
+  tags: SiteSyncTag[]
+): SiteSyncMediaTransfer {
+  return {
+    key: row.key,
+    ownerUsername,
+    originalName: row.original_name,
+    contentType: row.content_type,
+    size: row.size,
+    uploadedAt: row.uploaded_at,
+    mediaType: row.media_type,
+    thumbKey: row.thumb_key,
+    hlsKey: row.hls_key,
+    transcodeStatus: row.transcode_status as SiteSyncMediaTransfer['transcodeStatus'],
+    transcodeProgress: Number(row.transcode_progress ?? 0),
+    transcodePreset: row.transcode_preset,
+    transcodeError: row.transcode_error,
+    sourceDeleted: Number(row.source_deleted ?? 0) === 1,
+    tags
+  }
+}
+
+export function toSiteSyncMediaTransferWithTags(
+  row: ImageIndexRow,
+  ownerUsername: string | null
+): SiteSyncMediaTransfer {
+  const tags = getTagsForImageKeys([row.key]).get(row.key) ?? []
+  return toSiteSyncMediaTransfer(row, ownerUsername, tags)
+}
diff --git a/server/utils/site-sync/protocol.ts b/server/utils/site-sync/protocol.ts
new file mode 100644
index 0000000..ef65656
--- /dev/null
+++ b/server/utils/site-sync/protocol.ts
@@ -0,0 +1,59 @@
+import type { MediaType, TranscodeStatus } from '../storage/types'
+
+export interface SiteSyncTag {
+  name: string
+  color: string
+}
+
+export interface SiteSyncMediaTransfer {
+  key: string
+  ownerUsername: string | null
+  originalName: string
+  contentType: string
+  size: number
+  uploadedAt: string
+  mediaType: MediaType
+  thumbKey: string | null
+  hlsKey: string | null
+  transcodeStatus: TranscodeStatus
+  transcodeProgress: number
+  transcodePreset: string | null
+  transcodeError: string | null
+  sourceDeleted: boolean
+  tags: SiteSyncTag[]
+}
+
+export interface SiteSyncInventory {
+  users: string[]
+  mediaKeys: string[]
+  objects: Array<{ key: string, size: number }>
+}
+
+export interface SiteSyncMediaAsset {
+  key: string
+  size: number
+}
+
+export interface SiteSyncMediaBundle {
+  media: SiteSyncMediaTransfer
+  assets: SiteSyncMediaAsset[]
+}
+
+export interface SiteSyncMediaPage {
+  items: SiteSyncMediaBundle[]
+  totalMedia: number
+  nextCursor: string | null
+}
+
+export interface SiteSyncUsers {
+  users: string[]
+}
+
+export type SiteSyncDirection = 'push' | 'pull'
+
+export interface SiteSyncObjectOptions {
+  targetBaseUrl: string
+  token: string
+  conflictMode: 'skip' | 'overwrite'
+  direction?: SiteSyncDirection
+}
diff --git a/server/utils/site-sync/runner.test.ts b/server/utils/site-sync/runner.test.ts
new file mode 100644
index 0000000..c7d59af
--- /dev/null
+++ b/server/utils/site-sync/runner.test.ts
@@ -0,0 +1,55 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { fetchSiteSyncJson, retrySiteSyncOperation } from './runner'
+
+afterEach(() => {
+  vi.unstubAllGlobals()
+})
+
+describe('fetchSiteSyncJson', () => {
+  it('retries a broken connection up to three attempts', async () => {
+    const fetchMock = vi.fn()
+      .mockRejectedValueOnce(new Error('connection reset'))
+      .mockRejectedValueOnce(new Error('connection reset'))
+      .mockResolvedValueOnce(new Response('{"ok":true}', {
+        status: 200,
+        headers: { 'Content-Type': 'application/json' }
+      }))
+    vi.stubGlobal('fetch', fetchMock)
+
+    await expect(fetchSiteSyncJson('http://target/api', 'token')).resolves.toEqual({ ok: true })
+    expect(fetchMock).toHaveBeenCalledTimes(3)
+  })
+
+  it('retries client errors because every sync failure gets three attempts', async () => {
+    const fetchMock = vi.fn().mockImplementation(() => Promise.resolve(
+      new Response('{"message":"invalid"}', {
+        status: 400,
+        headers: { 'Content-Type': 'application/json' }
+      })
+    ))
+    vi.stubGlobal('fetch', fetchMock)
+
+    await expect(fetchSiteSyncJson('http://target/api', 'token')).rejects.toThrow('invalid')
+    expect(fetchMock).toHaveBeenCalledTimes(3)
+  })
+
+  it('fails after three server errors', async () => {
+    const fetchMock = vi.fn().mockImplementation(() => Promise.resolve(
+      new Response('{"message":"unavailable"}', {
+        status: 503,
+        headers: { 'Content-Type': 'application/json' }
+      })
+    ))
+    vi.stubGlobal('fetch', fetchMock)
+
+    await expect(fetchSiteSyncJson('http://target/api', 'token')).rejects.toThrow('unavailable')
+    expect(fetchMock).toHaveBeenCalledTimes(3)
+  })
+
+  it('retries local sync failures and stops after the third attempt', async () => {
+    const operation = vi.fn().mockRejectedValue(new Error('database is busy'))
+
+    await expect(retrySiteSyncOperation(operation)).rejects.toThrow('database is busy')
+    expect(operation).toHaveBeenCalledTimes(3)
+  })
+})
diff --git a/server/utils/site-sync/runner.ts b/server/utils/site-sync/runner.ts
new file mode 100644
index 0000000..407494f
--- /dev/null
+++ b/server/utils/site-sync/runner.ts
@@ -0,0 +1,641 @@
+import { basename } from 'node:path'
+import { contentTypeFromKey } from '../content-type'
+import {
+  getImageIndexRow,
+  listAllImageIndexRows,
+  type ImageIndexRow
+} from '../image-index'
+import {
+  findUserByUsername,
+  getPrimaryAdminUserId,
+  listUserIdUsernameMap
+} from '../db'
+import { collectMediaAssetKeys } from '../media-assets'
+import {
+  getActiveBackend,
+  getBackendForKey
+} from '../storage/resolver'
+import type { StorageBackend } from '../storage/types'
+import {
+  getBackupJob,
+  markJobDone,
+  markJobFailed,
+  updateBackupJob
+} from '../backup/jobs'
+import { applySiteSyncMedia } from './apply'
+import { toSiteSyncMediaTransferWithTags } from './manifest'
+import type {
+  SiteSyncDirection,
+  SiteSyncInventory,
+  SiteSyncMediaBundle,
+  SiteSyncMediaPage,
+  SiteSyncUsers
+} from './protocol'
+
+export interface SiteSyncOptions {
+  targetBaseUrl: string
+  conflictMode: 'skip' | 'overwrite'
+  direction: SiteSyncDirection
+}
+
+const tokens = (globalThis as typeof globalThis & {
+  __pichostSiteSyncTokens?: Map<string, string>
+}).__pichostSiteSyncTokens ?? new Map<string, string>()
+;(globalThis as typeof globalThis & {
+  __pichostSiteSyncTokens?: Map<string, string>
+}).__pichostSiteSyncTokens = tokens
+
+export function registerSiteSyncToken(jobId: string, token: string): void {
+  tokens.set(jobId, token)
+}
+
+async function streamToBuffer(stream: NodeJS.ReadableStream): Promise<Buffer> {
+  const chunks: Buffer[] = []
+  for await (const chunk of stream) {
+    chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk))
+  }
+  return Buffer.concat(chunks)
+}
+
+function targetUrl(baseUrl: string, path: string): string {
+  return `${baseUrl.replace(/\/+$/, '')}${path}`
+}
+
+async function responseError(response: Response): Promise<Error> {
+  const payload = await response.json().catch(() => null) as {
+    message?: string
+    statusMessage?: string
+  } | null
+  return new Error(payload?.message || payload?.statusMessage || `目标站点返回 ${response.status}`)
+}
+
+const SITE_SYNC_MAX_ATTEMPTS = 3
+
+export async function retrySiteSyncOperation<T>(
+  operation: () => Promise<T>
+): Promise<T> {
+  let lastError: Error | null = null
+  for (let attempt = 1; attempt <= SITE_SYNC_MAX_ATTEMPTS; attempt++) {
+    try {
+      return await operation()
+    } catch (error) {
+      lastError = error instanceof Error ? error : new Error('两站点同步失败')
+      if (attempt < SITE_SYNC_MAX_ATTEMPTS) {
+        await new Promise(resolve => setTimeout(resolve, attempt * 500))
+      }
+    }
+  }
+  throw lastError ?? new Error('两站点同步失败')
+}
+
+async function fetchSiteSyncJsonOnce<T>(
+  url: string,
+  token: string,
+  init?: RequestInit
+): Promise<T> {
+  const response = await fetch(url, {
+    ...init,
+    headers: {
+      'Auth-Token': token,
+      ...(init?.headers ?? {})
+    }
+  })
+  if (!response.ok) throw await responseError(response)
+  return await response.json() as T
+}
+
+export async function fetchSiteSyncJson<T>(
+  url: string,
+  token: string,
+  init?: RequestInit
+): Promise<T> {
+  return retrySiteSyncOperation(() => (
+    fetchSiteSyncJsonOnce<T>(url, token, init)
+  ))
+}
+
+async function uploadObject(
+  options: SiteSyncOptions,
+  token: string,
+  backend: StorageBackend,
+  row: ImageIndexRow,
+  ownerUsername: string | null,
+  key: string
+): Promise<void> {
+  const stored = await backend.head(key)
+  if (!stored) throw new Error(`源文件不存在：${key}`)
+  const bytes = await streamToBuffer(await backend.createStream(key))
+  const form = new FormData()
+  const isPrimary = key === row.key
+  form.append('key', key)
+  form.append('conflictMode', options.conflictMode)
+  form.append('ownerUsername', ownerUsername ?? '')
+  form.append('originalName', isPrimary ? row.original_name : basename(key))
+  form.append('uploadedAt', row.uploaded_at)
+  const contentType = isPrimary ? row.content_type : contentTypeFromKey(key)
+  form.append('contentType', contentType)
+  form.append(
+    'file',
+    new Blob([new Uint8Array(bytes)], { type: contentType }),
+    basename(key)
+  )
+
+  await fetchSiteSyncJsonOnce<{ success: boolean }>(
+    targetUrl(options.targetBaseUrl, '/api/site-sync/object'),
+    token,
+    { method: 'POST', body: form }
+  )
+}
+
+async function downloadSiteSyncObject(
+  options: SiteSyncOptions,
+  token: string,
+  key: string
+): Promise<Buffer> {
+  const response = await fetch(
+    targetUrl(
+      options.targetBaseUrl,
+      `/api/site-sync/object?key=${encodeURIComponent(key)}`
+    ),
+    {
+      headers: {
+        'Auth-Token': token
+      }
+    }
+  )
+  if (!response.ok) throw await responseError(response)
+  return Buffer.from(await response.arrayBuffer())
+}
+
+async function runSiteSyncPull(
+  jobId: string,
+  options: SiteSyncOptions,
+  token: string
+): Promise<void> {
+  const job = getBackupJob(jobId)
+  const checkpoint = job?.payload ?? {}
+  let lastMediaKey = typeof checkpoint.lastMediaKey === 'string'
+    ? checkpoint.lastMediaKey
+    : ''
+  let scanned = Number(checkpoint.scanned ?? 0)
+  let added = Number(checkpoint.added ?? 0)
+  let skipped = Number(checkpoint.skipped ?? 0)
+  let filesSynced = Number(checkpoint.filesSynced ?? 0)
+  let totalFiles = Number(checkpoint.totalFiles ?? 0)
+  let totalMedia = Number(checkpoint.totalMedia ?? job?.total ?? 0)
+  const failedKeys = new Set(
+    Array.isArray(checkpoint.failedKeys)
+      ? checkpoint.failedKeys.filter((key): key is string => typeof key === 'string')
+      : []
+  )
+
+  const saveCheckpoint = (message: string) => {
+    updateBackupJob(jobId, {
+      progress: scanned,
+      total: totalMedia,
+      message,
+      payload: {
+        targetBaseUrl: options.targetBaseUrl,
+        conflictMode: options.conflictMode,
+        direction: 'pull',
+        lastMediaKey,
+        scanned,
+        added,
+        skipped,
+        failed: failedKeys.size,
+        filesSynced,
+        totalFiles,
+        totalMedia,
+        failedKeys: [...failedKeys],
+        resumable: true
+      }
+    })
+  }
+  const progressMessage = (suffix = '') => (
+    `扫描 ${scanned}/${totalMedia || scanned} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size}${suffix}`
+  )
+  const failAndCheckpoint = (error: unknown) => {
+    const message = progressMessage(' · 已保存断点')
+    saveCheckpoint(message)
+    markJobFailed(
+      jobId,
+      error instanceof Error ? error.message : '从目标站点拉取失败',
+      message
+    )
+  }
+
+  try {
+    const targetUsers = new Set(
+      (await fetchSiteSyncJson<SiteSyncUsers>(
+        targetUrl(options.targetBaseUrl, '/api/site-sync/users'),
+        token
+      )).users
+    )
+    const localUserMap = listUserIdUsernameMap()
+    const localUsers = new Set(localUserMap.values())
+    const missingUsers = [...targetUsers].filter(name => !localUsers.has(name))
+    if (missingUsers.length) {
+      throw new Error(`当前站点缺少同名用户：${missingUsers.join('、')}`)
+    }
+
+    const backend = await retrySiteSyncOperation(() => getActiveBackend())
+    const actorUserId = job?.userId ?? getPrimaryAdminUserId() ?? 0
+    const readMediaPage = (path: string) => fetchSiteSyncJson<SiteSyncMediaPage>(
+      targetUrl(options.targetBaseUrl, path),
+      token
+    )
+
+    const processBundleOnce = async (
+      bundle: SiteSyncMediaBundle,
+      isRetry: boolean
+    ): Promise<'added' | 'skipped'> => {
+      const { media, assets } = bundle
+      if (
+        !isRetry
+        && options.conflictMode === 'skip'
+        && getImageIndexRow(media.key)
+      ) {
+        return 'skipped'
+      }
+
+      const owner = media.ownerUsername
+        ? findUserByUsername(media.ownerUsername)
+        : null
+      for (const asset of assets) {
+        if (
+          options.conflictMode === 'skip'
+          && await backend.head(asset.key)
+        ) {
+          continue
+        }
+        const bytes = await downloadSiteSyncObject(
+          options,
+          token,
+          asset.key
+        )
+        if (bytes.length !== asset.size) {
+          throw new Error(
+            `同步对象大小不一致：${asset.key}，预期 ${asset.size}，实际 ${bytes.length}`
+          )
+        }
+        const isPrimary = asset.key === media.key
+        await backend.put(asset.key, new Uint8Array(bytes), {
+          originalName: isPrimary ? media.originalName : basename(asset.key),
+          uploadedAt: media.uploadedAt,
+          contentType: isPrimary
+            ? media.contentType
+            : contentTypeFromKey(asset.key),
+          size: bytes.length,
+          userId: owner?.id ?? null,
+          mediaType: isPrimary
+            ? media.mediaType
+            : asset.key.startsWith('videos/')
+              ? 'video'
+              : asset.key.startsWith('files/')
+                ? 'file'
+                : 'image'
+        })
+      }
+
+      await applySiteSyncMedia(media, 'overwrite', actorUserId)
+      return 'added'
+    }
+    const processBundle = (bundle: SiteSyncMediaBundle, isRetry: boolean) => (
+      retrySiteSyncOperation(() => processBundleOnce(bundle, isRetry))
+    )
+    const recordOutcome = (outcome: 'added' | 'skipped', fileCount: number) => {
+      if (outcome === 'added') added += 1
+      else skipped += 1
+      filesSynced += fileCount
+      totalFiles = Math.max(totalFiles, filesSynced)
+    }
+
+    for (const key of [...failedKeys]) {
+      try {
+        const page = await readMediaPage(
+          `/api/site-sync/media?key=${encodeURIComponent(key)}`
+        )
+        const bundle = page.items[0]
+        if (!bundle) throw new Error(`目标媒体不存在：${key}`)
+        const outcome = await processBundle(bundle, true)
+        recordOutcome(outcome, bundle.assets.length)
+        failedKeys.delete(key)
+        if (key > lastMediaKey) lastMediaKey = key
+        saveCheckpoint(progressMessage())
+      } catch (error) {
+        failedKeys.add(key)
+        failAndCheckpoint(error)
+        return
+      }
+    }
+
+    let cursor = lastMediaKey
+    let lastCheckpointAt = 0
+    while (true) {
+      let page: SiteSyncMediaPage
+      try {
+        page = await readMediaPage(
+          `/api/site-sync/media?limit=50${cursor ? `&after=${encodeURIComponent(cursor)}` : ''}`
+        )
+      } catch (error) {
+        failAndCheckpoint(error)
+        return
+      }
+      totalMedia = Math.max(totalMedia, page.totalMedia)
+
+      for (const bundle of page.items) {
+        scanned += 1
+        try {
+          const outcome = await processBundle(bundle, false)
+          recordOutcome(outcome, bundle.assets.length)
+          failedKeys.delete(bundle.media.key)
+        } catch (error) {
+          failedKeys.add(bundle.media.key)
+          lastMediaKey = bundle.media.key
+          failAndCheckpoint(error)
+          return
+        }
+
+        lastMediaKey = bundle.media.key
+        const now = Date.now()
+        if (
+          now - lastCheckpointAt >= 1000
+          || scanned === totalMedia
+          || !page.nextCursor
+        ) {
+          saveCheckpoint(progressMessage())
+          lastCheckpointAt = now
+        }
+      }
+
+      if (!page.nextCursor) break
+      cursor = page.nextCursor
+    }
+
+    if (failedKeys.size) {
+      markJobFailed(
+        jobId,
+        `${failedKeys.size} 条媒体拉取失败`,
+        progressMessage()
+      )
+      saveCheckpoint(progressMessage())
+      return
+    }
+
+    totalFiles = filesSynced
+    markJobDone(jobId, {
+      message: `扫描 ${scanned}/${totalMedia || scanned} · 新增 ${added} · 跳过 ${skipped} · 失败 0`,
+      payload: {
+        targetBaseUrl: options.targetBaseUrl,
+        conflictMode: options.conflictMode,
+        direction: 'pull',
+        lastMediaKey,
+        scanned,
+        added,
+        skipped,
+        failed: 0,
+        filesSynced,
+        totalFiles,
+        totalMedia: totalMedia || scanned,
+        failedKeys: [],
+        resumable: false
+      }
+    })
+  } catch (error) {
+    failAndCheckpoint(error)
+  }
+}
+
+export async function runSiteSyncJob(
+  jobId: string,
+  options: SiteSyncOptions
+): Promise<void> {
+  const token = tokens.get(jobId)
+  if (!token) throw new Error('同步 Token 不可用，请重新发起任务')
+
+  try {
+    if (options.direction === 'pull') {
+      await runSiteSyncPull(jobId, options, token)
+      return
+    }
+
+    const inventory = await fetchSiteSyncJson<SiteSyncInventory>(
+      targetUrl(options.targetBaseUrl, '/api/site-sync/inventory'),
+      token
+    )
+    const targetUsers = new Set(inventory.users)
+    const targetMedia = new Set(inventory.mediaKeys)
+    const targetObjects = new Map(inventory.objects.map(item => [item.key, item.size]))
+    const rows = listAllImageIndexRows()
+    const ownerMap = listUserIdUsernameMap()
+    const job = getBackupJob(jobId)
+    const checkpoint = job?.payload ?? {}
+    let lastMediaKey = typeof checkpoint.lastMediaKey === 'string'
+      ? checkpoint.lastMediaKey
+      : ''
+    let scanned = Number(checkpoint.scanned ?? 0)
+    let added = Number(checkpoint.added ?? 0)
+    let skipped = Number(checkpoint.skipped ?? 0)
+    let filesSynced = Number(checkpoint.filesSynced ?? 0)
+    const failedKeys = new Set(
+      Array.isArray(checkpoint.failedKeys)
+        ? checkpoint.failedKeys.filter((key): key is string => typeof key === 'string')
+        : []
+    )
+
+    const missingUsers = [...new Set(
+      rows
+        .map(row => row.user_id == null ? null : ownerMap.get(row.user_id))
+        .filter((name): name is string => Boolean(name))
+    )].filter(name => !targetUsers.has(name))
+    if (missingUsers.length) {
+      throw new Error(`目标站点缺少同名用户：${missingUsers.join('、')}`)
+    }
+
+    const plans: Array<{
+      row: ImageIndexRow
+      ownerUsername: string | null
+      backend: StorageBackend
+      keys: string[]
+    }> = []
+    let totalFiles = 0
+    updateBackupJob(jobId, {
+      total: rows.length,
+      progress: scanned,
+      message: '正在统计同步文件…'
+    })
+
+    for (const row of rows) {
+      const backend = await getBackendForKey(row.key)
+      let assetKeys: string[]
+      try {
+        assetKeys = await collectMediaAssetKeys(row, backend)
+      } catch {
+        assetKeys = [
+          ...(!Number(row.source_deleted ?? 0) ? [row.key] : []),
+          ...(row.thumb_key ? [row.thumb_key] : []),
+          ...(row.hls_key ? [row.hls_key] : [])
+        ]
+      }
+      const keys = [...new Set(assetKeys)]
+      totalFiles += keys.length
+      plans.push({
+        row,
+        ownerUsername: row.user_id == null ? null : ownerMap.get(row.user_id) ?? null,
+        backend,
+        keys
+      })
+    }
+
+    const saveCheckpoint = (message: string) => {
+      updateBackupJob(jobId, {
+        progress: scanned,
+        total: rows.length,
+        message,
+        payload: {
+          targetBaseUrl: options.targetBaseUrl,
+          conflictMode: options.conflictMode,
+          direction: 'push',
+          lastMediaKey,
+          scanned,
+          added,
+          skipped,
+          failed: failedKeys.size,
+          filesSynced,
+          totalFiles,
+          failedKeys: [...failedKeys],
+          resumable: true
+        }
+      })
+    }
+
+    plans.sort((a, b) => (
+      a.row.key < b.row.key
+        ? -1
+        : a.row.key > b.row.key
+          ? 1
+          : 0
+    ))
+    lastMediaKey = lastMediaKey || ''
+    let lastCheckpointAt = 0
+    const processPlanOnce = async (plan: typeof plans[number], isRetry: boolean) => {
+      const { row, ownerUsername, backend, keys } = plan
+      if (
+        !isRetry
+        && options.conflictMode === 'skip'
+        && targetMedia.has(row.key)
+      ) {
+        skipped += 1
+        filesSynced = Math.min(totalFiles, filesSynced + keys.length)
+        failedKeys.delete(row.key)
+        return
+      }
+
+      for (const key of keys) {
+        const stored = await backend.head(key)
+        if (!stored) throw new Error(`源文件不存在：${key}`)
+        if (
+          options.conflictMode === 'skip'
+          && targetObjects.get(key) === stored.size
+        ) {
+          continue
+        }
+        await uploadObject(options, token, backend, row, ownerUsername, key)
+      }
+
+      await fetchSiteSyncJsonOnce<{ success: boolean }>(
+        targetUrl(options.targetBaseUrl, '/api/site-sync/media'),
+        token,
+        {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({
+            media: toSiteSyncMediaTransferWithTags(row, ownerUsername),
+            conflictMode: options.conflictMode
+          })
+        }
+      )
+
+      failedKeys.delete(row.key)
+      added += 1
+      filesSynced = Math.min(totalFiles, filesSynced + keys.length)
+    }
+    const processPlan = (
+      plan: typeof plans[number],
+      isRetry: boolean
+    ) => retrySiteSyncOperation(() => processPlanOnce(plan, isRetry))
+
+    const retryPlans = plans.filter(plan => failedKeys.has(plan.row.key))
+    for (const plan of retryPlans) {
+      try {
+        await processPlan(plan, true)
+        lastMediaKey = plan.row.key
+      } catch {
+        failedKeys.add(plan.row.key)
+        const message = `扫描 ${scanned}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size} · 已保存断点`
+        saveCheckpoint(message)
+        markJobFailed(jobId, '连续 3 次重试失败，已保存断点', message)
+        return
+      }
+    }
+
+    for (const plan of plans) {
+      if (plan.row.key <= lastMediaKey) continue
+      scanned += 1
+      try {
+        await processPlan(plan, false)
+      } catch {
+        failedKeys.add(plan.row.key)
+        lastMediaKey = plan.row.key
+        const message = `扫描 ${scanned}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size} · 已保存断点`
+        saveCheckpoint(message)
+        markJobFailed(jobId, '连续 3 次重试失败，已保存断点', message)
+        return
+      }
+      lastMediaKey = plan.row.key
+      const now = Date.now()
+      if (now - lastCheckpointAt >= 1000 || scanned === rows.length || failedKeys.size) {
+        saveCheckpoint(
+          `扫描 ${scanned}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size}`
+        )
+        lastCheckpointAt = now
+      }
+    }
+
+    if (failedKeys.size) {
+      markJobFailed(
+        jobId,
+        `${failedKeys.size} 条媒体同步失败`,
+        `扫描 ${scanned}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size}`
+      )
+      saveCheckpoint(
+        `扫描 ${scanned}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 ${failedKeys.size}`
+      )
+      return
+    }
+
+    markJobDone(jobId, {
+      message: `扫描 ${rows.length}/${rows.length} · 新增 ${added} · 跳过 ${skipped} · 失败 0`,
+      payload: {
+        targetBaseUrl: options.targetBaseUrl,
+        conflictMode: options.conflictMode,
+        direction: 'push',
+        lastMediaKey,
+        scanned: rows.length,
+        added,
+        skipped,
+        failed: 0,
+        filesSynced: totalFiles,
+        totalFiles,
+        failedKeys: [],
+        resumable: false
+      }
+    })
+  } catch (error) {
+    const message = error instanceof Error ? error.message : '两站点同步失败'
+    markJobFailed(jobId, message)
+    throw error
+  } finally {
+    tokens.delete(jobId)
+  }
+}