diff --git a/apps/desktop/main/paths/legacy-migration.ts b/apps/desktop/main/paths/legacy-migration.ts
index 93e03c80..3a4f8c19 100644
--- a/apps/desktop/main/paths/legacy-migration.ts
+++ b/apps/desktop/main/paths/legacy-migration.ts
@@ -6,7 +6,7 @@ import { app } from 'electron'
 import * as fs from 'node:fs'
 import * as path from 'node:path'
 import { loadConfig, writeConfigField } from '@openchatlab/config'
-import { copyDirMerge, copyDirRecursive, writeMigrationLog } from '../utils/pathUtils'
+import { arePathsEqual, copyDirMerge, copyDirRecursive, writeMigrationLog } from '../utils/pathUtils'
 import { shouldMarkUnifiedDirMigrationDone } from '../utils/unifiedDirMigration'
 import {
   ensureDir,
@@ -47,12 +47,8 @@ export function getLegacyDataDir(): string {
 export function needsLegacyMigration(): boolean {
   const legacyDir = getLegacyDataDir()
 
-  // 检查 Documents/ChatLab 是否存在
-  if (fs.existsSync(legacyDir)) {
-    return true
-  }
-
-  return false
+  // 用户可以主动将 Documents/ChatLab 设为当前数据目录，此时它不是待迁移的旧目录。
+  return fs.existsSync(legacyDir) && !arePathsEqual(legacyDir, getUserDataDir())
 }
 
 /**
@@ -138,6 +134,14 @@ export function migrateFromLegacyDir(): { success: boolean; migratedDirs: string
       return { success: true, migratedDirs: [] }
     }
 
+    // 迁移函数包含递归删除，必须在执行层再次阻止源目录与当前数据目录相同。
+    if (arePathsEqual(legacyDir, newDir)) {
+      const message = `Legacy migration skipped because source is the active data directory: ${legacyDir}`
+      console.warn(`[Paths] ${message}`)
+      writeMigrationLog(getLogsDir(), message, ensureDir)
+      return { success: true, migratedDirs: [] }
+    }
+
     // 获取旧目录下的所有子目录和文件
     const entries = fs.readdirSync(legacyDir, { withFileTypes: true })
     const dirsToMigrate = entries
@@ -198,6 +202,13 @@ export function removeLegacyDir(): boolean {
     return true
   }
 
+  if (arePathsEqual(legacyDir, getUserDataDir())) {
+    const message = `Legacy directory removal blocked because it is the active data directory: ${legacyDir}`
+    console.error(`[Paths] ${message}`)
+    writeMigrationLog(getLogsDir(), message, ensureDir)
+    return false
+  }
+
   try {
     fs.rmSync(legacyDir, { recursive: true, force: true })
     console.log(`[Paths] Removed legacy directory: ${legacyDir}`)
diff --git a/apps/desktop/main/paths/paths.test.ts b/apps/desktop/main/paths/paths.test.ts
index c00dd37c..cecf2e50 100644
--- a/apps/desktop/main/paths/paths.test.ts
+++ b/apps/desktop/main/paths/paths.test.ts
@@ -102,6 +102,17 @@ test('desktop paths preserve data across configured and legacy directory migrati
     fs.writeFileSync(path.join(legacyDir, 'databases', 'legacy.db'), 'legacy', 'utf-8')
     fs.writeFileSync(path.join(legacyDir, 'temp', 'stale.tmp'), 'temporary', 'utf-8')
 
+    configuredUserDataDir = legacyDir
+    paths.setCachedUserDataDir(legacyDir)
+    assert.equal(paths.needsLegacyMigration(), false)
+    const sameDirResult = paths.migrateFromLegacyDir()
+    assert.equal(sameDirResult.success, true)
+    assert.equal(fs.readFileSync(path.join(legacyDir, 'databases', 'legacy.db'), 'utf-8'), 'legacy')
+    assert.equal(paths.removeLegacyDir(), false)
+    assert.equal(fs.readFileSync(path.join(legacyDir, 'databases', 'legacy.db'), 'utf-8'), 'legacy')
+
+    configuredUserDataDir = targetDir
+    paths.setCachedUserDataDir(targetDir)
     assert.equal(paths.needsLegacyMigration(), true)
     const legacyResult = paths.migrateFromLegacyDir()
     assert.equal(legacyResult.success, true)
diff --git a/apps/desktop/main/utils/pathUtils.ts b/apps/desktop/main/utils/pathUtils.ts
index 15fb0be9..f047218e 100644
--- a/apps/desktop/main/utils/pathUtils.ts
+++ b/apps/desktop/main/utils/pathUtils.ts
@@ -28,6 +28,13 @@ function normalizePathForCompare(input: string): string {
   return process.platform === 'win32' ? normalized.toLowerCase() : normalized
 }
 
+/**
+ * 判断两个路径是否指向同一个规范化位置
+ */
+export function arePathsEqual(first: string, second: string): boolean {
+  return normalizePathForCompare(first) === normalizePathForCompare(second)
+}
+
 /**
  * 判断 child 是否为 parent 的子目录
  */