diff --git a/SpineThumbnailGenerateServer/js/library-watcher.js b/SpineThumbnailGenerateServer/js/library-watcher.js
index 0432083..2b52311 100644
--- a/SpineThumbnailGenerateServer/js/library-watcher.js
+++ b/SpineThumbnailGenerateServer/js/library-watcher.js
@@ -16,6 +16,24 @@ const QUIET_MS = 1000;
 // fs.watch 在网络盘/外置盘上可能漏事件，用低频兜底扫描补上。
 const FALLBACK_MS = 30000;
 
+/** 删除指定目录中超过保留时间的本插件临时文件。 */
+function cleanupStaleFiles(directory, prefix, maxAgeMs, now = Date.now()) {
+	let names;
+	try { names = fs.readdirSync(directory); } catch (error) { return 0; }
+	let removed = 0;
+	for (const name of names) {
+		if (!name.startsWith(prefix)) continue;
+		const file = path.join(directory, name);
+		try {
+			const stat = fs.lstatSync(file);
+			if (!stat.isFile() || now - stat.mtimeMs < maxAgeMs) continue;
+			fs.unlinkSync(file);
+			removed += 1;
+		} catch (error) { /* 单个文件失败不影响其余清理和监听 */ }
+	}
+	return removed;
+}
+
 function createLibraryWatcher(options) {
 	const onBatch = options.onBatch || (() => {});
 	const onLog = options.onLog || (() => {});
@@ -94,7 +112,7 @@ function createLibraryWatcher(options) {
 
 // 同时支持两种加载方式：Node 里用 require（跑测试），插件页面里用 <script> 标签。
 // service 插件页面的 require 解析基准不是插件目录，所以页面里必须走 script 标签。
-const libraryWatcherApi = { createLibraryWatcher, QUIET_MS, FALLBACK_MS };
+const libraryWatcherApi = { createLibraryWatcher, cleanupStaleFiles, QUIET_MS, FALLBACK_MS };
 // 优先挂 window：Eagle 插件页面里也存在 module 对象（它有 Node 模块系统），
 // 先判断 module 会让页面拿到模块却取不到 window 上的名字。Node 里没有 window，自然走 require 分支。
 if (typeof window !== 'undefined') window.SpineThumbLibraryWatcher = libraryWatcherApi;
diff --git a/SpineThumbnailGenerateServer/js/plugin.js b/SpineThumbnailGenerateServer/js/plugin.js
index 4e81ad0..4ea80a6 100644
--- a/SpineThumbnailGenerateServer/js/plugin.js
+++ b/SpineThumbnailGenerateServer/js/plugin.js
@@ -2,7 +2,7 @@
 
 // 每次改动递增。Eagle 里的 service 插件是启动时加载并常驻的，改完代码必须重新加载插件
 // 才会生效；状态栏会显示这个版本号，方便确认加载的到底是不是最新代码。
-const VERSION = 'v60';
+const VERSION = 'v61';
 
 const path = require('path');
 const os = require('os');
@@ -19,7 +19,7 @@ if (missing.length) {
 	document.getElementById('status').textContent = '本地模块未加载：' + missing.join(', ');
 	throw new Error('本地模块未加载，请检查 index.html 里 script 的顺序：' + missing.join(', '));
 }
-const { createLibraryWatcher } = window.SpineThumbLibraryWatcher;
+const { createLibraryWatcher, cleanupStaleFiles } = window.SpineThumbLibraryWatcher;
 const { scanSpineItems } = window.SpineThumbSpineAssets;
 const { renderThumbnailAuto, withTimeout } = window.SpineThumbRenderer;
 const settingsStore = window.SpineThumbSettings;
@@ -42,6 +42,7 @@ const stats = { batches: 0, added: 0, spine: 0, complete: 0, generated: 0, skipp
 const PROGRESS_MIN_DYNAMIC = 10;
 // 弹窗上的「停止」按钮会把动作写进这个文件，宿主读回来执行暂停/继续/取消。
 const CONTROL_FILE = path.join(os.tmpdir(), 'spine-thumbnail-progress-control.json');
+const STALE_TEMP_AGE_MS = 24 * 60 * 60 * 1000;
 let settings = { ...settingsStore.DEFAULTS };
 let libraryPath = null;
 let imagesDir = null;
@@ -290,6 +291,7 @@ async function processQueue() {
 		runStats = null;
 		runShowsProgress = false;
 		if (run && showsProgress) finishRun(run);
+		cleanupStaleFiles(os.tmpdir(), 'spine-thumb-', STALE_TEMP_AGE_MS);
 	}
 }
 
@@ -492,6 +494,7 @@ filtersEl.addEventListener('click', (event) => {
 
 // 先确认脚本本身执行到了这里，再谈 Eagle 事件有没有来。
 document.getElementById('status').textContent = '脚本已加载 ' + VERSION + '，等待 Eagle 事件…';
+cleanupStaleFiles(os.tmpdir(), 'spine-thumb-', STALE_TEMP_AGE_MS);
 
 if (typeof eagle === 'undefined') {
 	setStatus('eagle API 未注入');
diff --git a/SpineThumbnailGenerateServer/tests/temp-cleanup.test.js b/SpineThumbnailGenerateServer/tests/temp-cleanup.test.js
new file mode 100644
index 0000000..da78267
--- /dev/null
+++ b/SpineThumbnailGenerateServer/tests/temp-cleanup.test.js
@@ -0,0 +1,28 @@
+'use strict';
+
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+const { cleanupStaleFiles } = require('../js/library-watcher.js');
+
+const directory = fs.mkdtempSync(path.join(os.tmpdir(), 'spine-thumb-cleanup-'));
+const now = Date.now();
+const old = path.join(directory, 'spine-thumb-old.webp');
+const fresh = path.join(directory, 'spine-thumb-fresh.webp');
+const unrelated = path.join(directory, 'other-old.webp');
+
+try {
+	for (const file of [old, fresh, unrelated]) fs.writeFileSync(file, 'x');
+	const oldTime = new Date(now - 25 * 60 * 60 * 1000);
+	fs.utimesSync(old, oldTime, oldTime);
+	fs.utimesSync(unrelated, oldTime, oldTime);
+
+	assert.equal(cleanupStaleFiles(directory, 'spine-thumb-', 24 * 60 * 60 * 1000, now), 1);
+	assert.equal(fs.existsSync(old), false);
+	assert.equal(fs.existsSync(fresh), true);
+	assert.equal(fs.existsSync(unrelated), true);
+	console.log('PASS: 只清理超过 24 小时的本插件临时文件');
+} finally {
+	fs.rmSync(directory, { recursive: true, force: true });
+}