diff --git a/mindspace-workspace-sync.mjs b/mindspace-workspace-sync.mjs
index 1fdf055..e562aa9 100644
--- a/mindspace-workspace-sync.mjs
+++ b/mindspace-workspace-sync.mjs
@@ -154,6 +154,29 @@ export function createWorkspaceAssetSync({
     return new Map(rows.map((row) => [row.original_filename, row]));
   };
 
+  /** Deleted workspace assets still own workspace:// storage_key rows — restore instead of re-import. */
+  const loadDeletedWorkspaceAssetsByFilename = async (userId, categoryId) => {
+    const [rows] = await pool.query(
+      `SELECT a.id, a.original_filename, a.checksum, a.size_bytes, a.current_version_id, a.status
+       FROM h5_assets a
+       WHERE a.user_id = ? AND a.category_id = ? AND a.status = 'deleted' AND a.source_type = 'workspace'`,
+      [userId, categoryId],
+    );
+    return new Map(rows.map((row) => [row.original_filename, row]));
+  };
+
+  const findDeletedWorkspaceAssetByStorageKey = async (userId, storageKey) => {
+    const [rows] = await pool.query(
+      `SELECT a.id, a.original_filename, a.checksum, a.size_bytes, a.current_version_id, a.status
+       FROM h5_asset_versions v
+       JOIN h5_assets a ON a.id = v.asset_id AND a.user_id = ?
+       WHERE v.storage_key = ? AND a.status = 'deleted' AND a.source_type = 'workspace'
+       LIMIT 1`,
+      [userId, storageKey],
+    );
+    return rows[0] ?? null;
+  };
+
   /** Skip re-importing workspace files the user already deleted (checksum unchanged). */
   const loadDeletedWorkspaceChecksums = async (userId, categoryId) => {
     const [rows] = await pool.query(
@@ -307,7 +330,7 @@ export function createWorkspaceAssetSync({
         throw Object.assign(new Error('用户空间不可用'), { code: 'space_unavailable' });
       }
       const [assetRows] = await conn.query(
-        `SELECT id, current_version_id, size_bytes, checksum
+        `SELECT id, current_version_id, size_bytes, checksum, status
          FROM h5_assets
          WHERE id = ? AND user_id = ?
          LIMIT 1
@@ -318,6 +341,7 @@ export function createWorkspaceAssetSync({
       if (!currentAsset) {
         throw Object.assign(new Error('工作区资产不存在'), { code: 'asset_not_found' });
       }
+      const wasDeleted = currentAsset.status === 'deleted';
 
       const detectedMimeType = assetInternals.detectMimeType(buffer, file.filename);
       if (!detectedMimeType) {
@@ -375,7 +399,8 @@ export function createWorkspaceAssetSync({
       await conn.query(
         `UPDATE h5_assets
          SET size_bytes = ?, checksum = ?, mime_type = ?,
-             asset_type = ?, risk_level = ?, status = ?, workspace_relative_path = ?, updated_at = ?
+             asset_type = ?, risk_level = ?, status = ?, workspace_relative_path = ?,
+             deleted_at = NULL, updated_at = ?
          WHERE id = ? AND user_id = ?`,
         [
           buffer.length,
@@ -406,16 +431,17 @@ export function createWorkspaceAssetSync({
           currentAsset.id,
         ],
       );
-      if (sizeDelta !== 0) {
+      const quotaDelta = wasDeleted ? buffer.length : sizeDelta;
+      if (quotaDelta !== 0) {
         await conn.query(
           `UPDATE h5_user_spaces SET used_bytes = GREATEST(0, used_bytes + ?), updated_at = ?
            WHERE id = ? AND user_id = ?`,
-          [sizeDelta, now, category.space_id, userId],
+          [quotaDelta, now, category.space_id, userId],
         );
       }
       await conn.commit();
       return {
-        action: 'updated',
+        action: wasDeleted ? 'restored' : 'updated',
         assetId: currentAsset.id,
         filename: file.filename,
         checksum,
@@ -490,6 +516,7 @@ export function createWorkspaceAssetSync({
     if (!category) return { imported: 0, updated: 0, skipped: 0 };
 
     const existingByName = await loadExistingAssets(userId, category.id);
+    const deletedByName = await loadDeletedWorkspaceAssetsByFilename(userId, category.id);
     const deletedWorkspaceChecksums = await loadDeletedWorkspaceChecksums(userId, category.id);
     let imported = 0;
     let updated = 0;
@@ -524,6 +551,31 @@ export function createWorkspaceAssetSync({
         existing.size_bytes = buffer.length;
         updated += 1;
       } else {
+        const storageKey = buildWorkspaceStorageKey(
+          userId,
+          category.category_code,
+          file.filename,
+        );
+        const deletedExisting =
+          deletedByName.get(file.filename)
+          ?? (await findDeletedWorkspaceAssetByStorageKey(userId, storageKey));
+        if (deletedExisting) {
+          const result = await updateWorkspaceFile(userId, category, deletedExisting, file, buffer);
+          if (result.action === 'skipped') {
+            skipped += 1;
+            continue;
+          }
+          await registerWorkspaceArtifactForConversation(userId, source, result);
+          deletedByName.delete(deletedExisting.original_filename);
+          existingByName.set(deletedExisting.original_filename, {
+            id: deletedExisting.id,
+            checksum,
+            size_bytes: buffer.length,
+            current_version_id: deletedExisting.current_version_id,
+          });
+          updated += 1;
+          continue;
+        }
         const result = await importWorkspaceFile(userId, category, file, buffer);
         await registerWorkspaceArtifactForConversation(userId, source, result);
         existingByName.set(file.filename, { checksum });
diff --git a/mindspace-workspace-sync.test.mjs b/mindspace-workspace-sync.test.mjs
index 08e5a20..0396415 100644
--- a/mindspace-workspace-sync.test.mjs
+++ b/mindspace-workspace-sync.test.mjs
@@ -476,3 +476,160 @@ test('syncUserWorkspace imports nested workspace files into asset library', asyn
   assert.equal(result.imported, 1);
   assert.equal(state.assets[0].original_filename, '暑假实习报告/report.csv');
 });
+
+test('syncUserWorkspace restores deleted workspace asset instead of duplicate storage_key insert', async () => {
+  const h5Root = await fs.mkdtemp(path.join(os.tmpdir(), 'h5-sync-deleted-restore-'));
+  const storageRoot = path.join(h5Root, 'data', 'mindspace');
+  const workspace = resolveUserWorkspaceRoot(h5Root, { id: 'user-1', username: 'john' });
+  await fs.mkdir(path.join(workspace, 'public'), { recursive: true });
+  await fs.writeFile(
+    path.join(workspace, 'public', 'simple-page.html'),
+    '<!doctype html><html><body>restored</body></html>',
+  );
+
+  const storageKey = 'workspace://user-1/public/simple-page.html';
+  const state = {
+    categories: [
+      { id: 'cat-public', user_id: 'user-1', space_id: 'space-1', category_code: 'public' },
+    ],
+    spaces: [
+      {
+        id: 'space-1',
+        user_id: 'user-1',
+        quota_bytes: 5 * 1024 * 1024,
+        used_bytes: 0,
+        reserved_bytes: 0,
+        status: 'active',
+      },
+    ],
+    assets: [
+      {
+        id: 'asset-deleted-1',
+        user_id: 'user-1',
+        category_id: 'cat-public',
+        original_filename: 'simple-page.html',
+        checksum: 'old-checksum',
+        size_bytes: 10,
+        current_version_id: 'version-deleted-1',
+        status: 'deleted',
+        source_type: 'workspace',
+        deleted_at: Date.now(),
+      },
+    ],
+    versions: [
+      {
+        id: 'version-deleted-1',
+        asset_id: 'asset-deleted-1',
+        storage_key: storageKey,
+        scan_status: 'passed',
+      },
+    ],
+  };
+
+  const pool = {
+    async query(sql, params = []) {
+      if (sql.includes('FROM h5_space_categories c') && sql.includes('category_code = ?')) {
+        const category = state.categories.find(
+          (item) => item.user_id === params[0] && item.category_code === params[1],
+        );
+        return [category ? [category] : []];
+      }
+      if (sql.includes('FROM h5_asset_versions v') && sql.includes('storage_key = ?')) {
+        const row = state.versions.find((item) => item.storage_key === params[1]);
+        if (!row) return [[]];
+        const asset = state.assets.find(
+          (item) => item.id === row.asset_id && item.user_id === params[0] && item.status === 'deleted',
+        );
+        return asset
+          ? [[{
+            id: asset.id,
+            original_filename: asset.original_filename,
+            checksum: asset.checksum,
+            size_bytes: asset.size_bytes,
+            current_version_id: asset.current_version_id,
+            status: asset.status,
+          }]]
+          : [[]];
+      }
+      if (sql.includes('FROM h5_assets')) {
+        const assets = state.assets.filter((item) => {
+          if (item.user_id !== params[0] || item.category_id !== params[1]) return false;
+          if (sql.includes("status <> 'deleted'") && item.status === 'deleted') return false;
+          if (sql.includes("status = 'deleted'") && item.status !== 'deleted') return false;
+          if (sql.includes("source_type = 'workspace'") && item.source_type !== 'workspace') {
+            return false;
+          }
+          return true;
+        });
+        return [assets];
+      }
+      return [[]];
+    },
+    async getConnection() {
+      return {
+        async beginTransaction() {},
+        async commit() {},
+        async rollback() {},
+        release() {},
+        async query(sql, params = []) {
+          if (sql.includes('FROM h5_user_spaces') && sql.includes('FOR UPDATE')) {
+            return [[state.spaces[0]]];
+          }
+          if (sql.includes('FROM h5_assets') && sql.includes('FOR UPDATE')) {
+            const asset = state.assets.find(
+              (item) => item.id === params[0] && item.user_id === params[1],
+            );
+            return [asset ? [asset] : []];
+          }
+          if (sql.includes('UPDATE h5_assets') && sql.includes('deleted_at = NULL')) {
+            const asset = state.assets.find(
+              (item) => item.id === params[8] && item.user_id === params[9],
+            );
+            asset.size_bytes = params[0];
+            asset.checksum = params[1];
+            asset.status = params[5];
+            asset.deleted_at = null;
+            return [[]];
+          }
+          if (sql.includes('UPDATE h5_asset_versions')) {
+            const version = state.versions.find(
+              (item) => item.id === params[6] && item.asset_id === params[7],
+            );
+            version.size_bytes = params[0];
+            version.checksum = params[1];
+            version.scan_status = params[4];
+            return [[]];
+          }
+          if (sql.includes('used_bytes = GREATEST')) {
+            state.spaces[0].used_bytes += params[0];
+            return [[]];
+          }
+          if (sql.includes('INSERT INTO h5_assets')) {
+            throw new Error('should not insert a new asset when restoring deleted workspace file');
+          }
+          if (sql.includes('INSERT INTO h5_asset_versions')) {
+            throw new Error('should not insert a new asset version when restoring deleted workspace file');
+          }
+          return pool.query(sql, params);
+        },
+      };
+    },
+  };
+
+  const sync = createWorkspaceAssetSync({
+    pool,
+    storageRoot,
+    h5Root,
+    maxFileBytes: 1024 * 1024,
+    idFactory: () => 'unused-id',
+  });
+
+  const result = await sync.syncUserWorkspace('user-1', { categoryCode: 'public' });
+  assert.equal(result.updated, 1);
+  assert.equal(state.assets.length, 1);
+  assert.equal(state.assets[0].status, 'ready');
+  assert.equal(state.assets[0].deleted_at, null);
+  assert.equal(state.versions.length, 1);
+  assert.equal(state.versions[0].storage_key, storageKey);
+  assert.ok(state.spaces[0].used_bytes > 0);
+});