diff --git a/app/components/storage/SiteSyncCard.vue b/app/components/storage/SiteSyncCard.vue
index 1989e7d..5e7f03e 100644
--- a/app/components/storage/SiteSyncCard.vue
+++ b/app/components/storage/SiteSyncCard.vue
@@ -3,6 +3,7 @@ import type {
   SiteSyncDirection,
   SiteSyncRequest
 } from '~/types/backup'
+import { loadSiteSyncForm, saveSiteSyncForm } from '~/utils/site-sync-form'
 
 const props = defineProps<{
   busy: boolean
@@ -30,42 +31,15 @@ const conflictMode = ref<'skip' | 'overwrite'>('skip')
 const direction = ref<SiteSyncDirection>('push')
 const scope = ref<'all' | 'image' | 'video' | 'file'>('all')
 
-/** 目标站点地址与 Token 自动保存 24 小时 */
-const FORM_STORAGE_KEY = 'pichost.site-sync-form'
-const FORM_TTL_MS = 24 * 60 * 60 * 1000
-
 function loadSavedForm() {
   if (!import.meta.client) return
-  try {
-    const raw = localStorage.getItem(FORM_STORAGE_KEY)
-    if (!raw) return
-    const data = JSON.parse(raw) as {
-      targetBaseUrl?: string
-      token?: string
-      savedAt?: number
-    }
-    if (!data.savedAt || Date.now() - data.savedAt > FORM_TTL_MS) {
-      localStorage.removeItem(FORM_STORAGE_KEY)
-      return
-    }
-    if (data.targetBaseUrl) targetBaseUrl.value = data.targetBaseUrl
-    if (data.token) token.value = data.token
-  } catch {
-    localStorage.removeItem(FORM_STORAGE_KEY)
-  }
+  const saved = loadSiteSyncForm()
+  if (saved?.targetBaseUrl) targetBaseUrl.value = saved.targetBaseUrl
+  if (saved?.token) token.value = saved.token
 }
 
 function persistForm() {
-  if (!import.meta.client) return
-  try {
-    localStorage.setItem(FORM_STORAGE_KEY, JSON.stringify({
-      targetBaseUrl: targetBaseUrl.value,
-      token: token.value,
-      savedAt: Date.now()
-    }))
-  } catch {
-    // 存储不可用时忽略
-  }
+  saveSiteSyncForm(targetBaseUrl.value, token.value)
 }
 
 watch([targetBaseUrl, token], persistForm)
diff --git a/app/components/storage/SiteSyncSelectedDialog.vue b/app/components/storage/SiteSyncSelectedDialog.vue
index ac0827c..19a6323 100644
--- a/app/components/storage/SiteSyncSelectedDialog.vue
+++ b/app/components/storage/SiteSyncSelectedDialog.vue
@@ -1,4 +1,6 @@
 <script setup lang="ts">
+import { loadSiteSyncForm, saveSiteSyncForm } from '~/utils/site-sync-form'
+
 const props = defineProps<{
   open: boolean
   keys: string[]
@@ -17,6 +19,19 @@ const token = ref('')
 const conflictMode = ref<'skip' | 'overwrite'>('skip')
 const busy = ref(false)
 
+watch(() => props.open, (open) => {
+  if (!open) return
+  const saved = loadSiteSyncForm()
+  if (saved) {
+    targetBaseUrl.value = saved.targetBaseUrl
+    token.value = saved.token
+  }
+}, { immediate: true })
+
+watch([targetBaseUrl, token], () => {
+  saveSiteSyncForm(targetBaseUrl.value, token.value)
+})
+
 const canSubmit = computed(() =>
   !busy.value
   && props.keys.length > 0
diff --git a/app/utils/site-sync-form.test.ts b/app/utils/site-sync-form.test.ts
new file mode 100644
index 0000000..ed0ab44
--- /dev/null
+++ b/app/utils/site-sync-form.test.ts
@@ -0,0 +1,50 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import {
+  loadSiteSyncForm,
+  saveSiteSyncForm,
+  SITE_SYNC_FORM_STORAGE_KEY
+} from './site-sync-form'
+
+function createStorage(): Storage {
+  const values = new Map<string, string>()
+  return {
+    get length() {
+      return values.size
+    },
+    clear: () => values.clear(),
+    getItem: key => values.get(key) ?? null,
+    key: index => [...values.keys()][index] ?? null,
+    removeItem: key => values.delete(key),
+    setItem: (key, value) => values.set(key, value)
+  }
+}
+
+describe('site sync form cache', () => {
+  afterEach(() => {
+    vi.useRealTimers()
+    vi.unstubAllGlobals()
+  })
+
+  it('reads values saved by another component', () => {
+    vi.stubGlobal('localStorage', createStorage())
+    saveSiteSyncForm('http://127.0.0.1:3010', 'secret-token')
+
+    expect(loadSiteSyncForm()).toEqual({
+      targetBaseUrl: 'http://127.0.0.1:3010',
+      token: 'secret-token'
+    })
+  })
+
+  it('drops the cache after 24 hours', () => {
+    const storage = createStorage()
+    vi.stubGlobal('localStorage', storage)
+    vi.useFakeTimers()
+    vi.setSystemTime(new Date('2026-10-19T00:00:00Z'))
+    saveSiteSyncForm('http://target', 'token')
+
+    vi.setSystemTime(new Date('2026-10-20T00:00:01Z'))
+
+    expect(loadSiteSyncForm()).toBeNull()
+    expect(storage.getItem(SITE_SYNC_FORM_STORAGE_KEY)).toBeNull()
+  })
+})
diff --git a/app/utils/site-sync-form.ts b/app/utils/site-sync-form.ts
new file mode 100644
index 0000000..befac0f
--- /dev/null
+++ b/app/utils/site-sync-form.ts
@@ -0,0 +1,52 @@
+export const SITE_SYNC_FORM_STORAGE_KEY = 'pichost.site-sync-form'
+export const SITE_SYNC_FORM_TTL_MS = 24 * 60 * 60 * 1000
+
+export interface SiteSyncFormCache {
+  targetBaseUrl: string
+  token: string
+}
+
+function getStorage(): Storage | null {
+  return typeof localStorage === 'undefined' ? null : localStorage
+}
+
+export function loadSiteSyncForm(): SiteSyncFormCache | null {
+  const storage = getStorage()
+  if (!storage) return null
+
+  try {
+    const raw = storage.getItem(SITE_SYNC_FORM_STORAGE_KEY)
+    if (!raw) return null
+    const data = JSON.parse(raw) as {
+      targetBaseUrl?: unknown
+      token?: unknown
+      savedAt?: unknown
+    }
+    if (typeof data.savedAt !== 'number' || Date.now() - data.savedAt > SITE_SYNC_FORM_TTL_MS) {
+      storage.removeItem(SITE_SYNC_FORM_STORAGE_KEY)
+      return null
+    }
+    return {
+      targetBaseUrl: typeof data.targetBaseUrl === 'string' ? data.targetBaseUrl : '',
+      token: typeof data.token === 'string' ? data.token : ''
+    }
+  } catch {
+    storage.removeItem(SITE_SYNC_FORM_STORAGE_KEY)
+    return null
+  }
+}
+
+export function saveSiteSyncForm(targetBaseUrl: string, token: string): void {
+  const storage = getStorage()
+  if (!storage) return
+
+  try {
+    storage.setItem(SITE_SYNC_FORM_STORAGE_KEY, JSON.stringify({
+      targetBaseUrl,
+      token,
+      savedAt: Date.now()
+    }))
+  } catch {
+    // 存储不可用时忽略
+  }
+}