diff --git a/app/chain/search/provider.py b/app/chain/search/provider.py
index e03a0d623..18106aad2 100644
--- a/app/chain/search/provider.py
+++ b/app/chain/search/provider.py
@@ -156,14 +156,14 @@ class _SearchProviderSyncOwner(_SearchOwnerBase):
 
     @staticmethod
     def _torrent_keyword(
-        keyword: str,
+        keyword: Optional[str],
         mediainfo: Optional[MediaInfo],
         area: Optional[str],
     ) -> str:
-        """投影站点实际请求关键字，IMDb 搜索只在计划边界转换一次。"""
+        """投影站点实际请求关键字，缺少 IMDb ID 时回退媒体标题。"""
         if area == "imdbid" and mediainfo:
-            return mediainfo.imdb_id or keyword
-        return keyword
+            return mediainfo.imdb_id or keyword or mediainfo.title or ""
+        return keyword or ""
 
     @staticmethod
     def _torrent_type(
@@ -378,8 +378,9 @@ class _SearchProviderSyncOwner(_SearchOwnerBase):
         """通过共享线程 owner 按站点顺序翻页并汇总同步 provider 结果。"""
         indexer_sites = self._sync_indexers(sites)
         media_type = self._torrent_type(mediainfo, mtype)
+        search_keyword = self._torrent_keyword(keyword, mediainfo, area)
         plugin_results = self.search_plugin_torrents(
-            keyword=keyword,
+            keyword=search_keyword,
             mtype=media_type,
             page=page,
         )
@@ -391,7 +392,6 @@ class _SearchProviderSyncOwner(_SearchOwnerBase):
         start_time = datetime.now()
         search_pages = self._build_search_pages(page)
         results = list(plugin_results)
-        search_keyword = self._torrent_keyword(keyword, mediainfo, area)
 
         progress.start()
         try:
@@ -672,13 +672,13 @@ class SearchProviderOwner(_SearchProviderSyncOwner):
         """构造种子 provider 的 canonical 事件流。"""
         indexer_sites = await self._async_indexers(sites)
         media_type = self._torrent_type(mediainfo, mtype)
+        search_keyword = self._torrent_keyword(keyword, mediainfo, area)
         plugin_results = await self.async_search_plugin_torrents(
-            keyword=keyword,
+            keyword=search_keyword,
             mtype=media_type,
             page=page,
         )
         search_pages = self._build_search_pages(page)
-        search_keyword = self._torrent_keyword(keyword, mediainfo, area)
 
         async def search_site_page(
             site: SiteIndexer,
diff --git a/app/chain/subscribe/search.py b/app/chain/subscribe/search.py
index 291c8ade4..5c7cd55ce 100644
--- a/app/chain/subscribe/search.py
+++ b/app/chain/subscribe/search.py
@@ -830,7 +830,7 @@ class SubscribeSearchOwner(_SubscribeSearchQueueOwner):
             no_exists=no_exists,
             sites=self.get_sub_sites(subscribe),
             rule_groups=subscribe.filter_groups or get_configured_system_config().get(rule_key) or [],
-            area="imdbid" if subscribe.search_imdbid else "title",
+            area="imdbid" if subscribe.search_imdbid and mediainfo.imdb_id else "title",
             custom_words=subscribe.custom_words.split("\n") if subscribe.custom_words else None,
             filter_params=self.get_params(subscribe),
         )
diff --git a/tests/test_search_sync_async_parity.py b/tests/test_search_sync_async_parity.py
index fb7219357..ca3546262 100644
--- a/tests/test_search_sync_async_parity.py
+++ b/tests/test_search_sync_async_parity.py
@@ -117,6 +117,14 @@ def test_id_search_sync_async_share_request_and_missing_plan(monkeypatch):
     assert saved_sync == saved_async
 
 
+def test_imdb_search_falls_back_to_media_title_without_imdb_id():
+    """IMDb 搜索缺少 IMDb ID 且没有调用方关键字时应请求媒体标题。"""
+    target = _media()
+
+    assert SearchChain._torrent_keyword(None, target, "imdbid") == target.title
+    assert SearchChain._torrent_keyword("自定义标题", target, "imdbid") == "自定义标题"
+
+
 def test_media_process_sync_async_share_keyword_stop_decision(monkeypatch):
     """双入口应按相同关键字顺序搜索，并在首个有效结果后同时停止。"""
     chain = _chain()