diff --git a/backend/api/server.py b/backend/api/server.py
index 6a712cc..5c32ebe 100644
--- a/backend/api/server.py
+++ b/backend/api/server.py
@@ -1725,6 +1725,9 @@ def create_app(state: AgentState) -> FastAPI:
             ):
                 continue
             title = session_metadata.get('title')
+            title_source = session_metadata.get('title_source')
+            if isinstance(title, str) and title_source != 'manual':
+                title = _clean_session_title(title)
             if not isinstance(title, str) or not title.strip():
                 title = None
             preview = ''
@@ -3917,6 +3920,8 @@ def _read_session_title(directory: Path, session_id: str | None) -> str | None:
         return None
     title = metadata.get('title')
     if isinstance(title, str) and title.strip():
+        if metadata.get('title_source') != 'manual':
+            return _clean_session_title(title)
         return title.strip()
     return None
 
@@ -4044,8 +4049,30 @@ def _generate_session_title(
 
 
 def _clean_session_title(value: str) -> str | None:
-    title = ' '.join(value.strip().strip('"\'“”‘’`').split())
+    raw = value.strip()
+    if not raw:
+        return None
+    raw = re.sub(r'(?is)<analysis>.*?</analysis>', '', raw)
+    raw = re.sub(r'(?is)<think>.*?</think>', '', raw)
+    if re.search(r'(?i)<\s*(analysis|think)\b', raw):
+        return None
+    lines = [line.strip() for line in raw.replace('\r', '\n').split('\n')]
+    title = next((line for line in reversed(lines) if line), '')
+    title = re.sub(r'^\s*(?:[-*#>\d.、\s]+)', '', title)
+    title = re.sub(
+        r'^(?:会话标题|标题|短标题|生成标题|session title)\s*[:：]\s*',
+        '',
+        title,
+        flags=re.IGNORECASE,
+    )
+    title = title.strip().strip('"\'“”‘’`*_ ')
+    title = re.sub(r'\*\*(.*?)\*\*', r'\1', title)
+    title = ' '.join(title.split())
     title = title.rstrip('。.!！?？')
+    if re.search(r'(?i)\b(generating|generate|thinking|reasoning)\b', title):
+        return None
+    if '<' in title or '>' in title:
+        return None
     if not title:
         return None
     return title[:24].rstrip()
diff --git a/tests/test_gui_server.py b/tests/test_gui_server.py
index aadb983..11f512f 100644
--- a/tests/test_gui_server.py
+++ b/tests/test_gui_server.py
@@ -22,6 +22,7 @@ from backend.api.server import (
     AgentState,
     create_app,
     _bash_bg_manager,
+    _clean_session_title,
     _derive_initial_session_title,
     _ensure_session_title,
     _generate_session_title,
@@ -860,6 +861,35 @@ class GuiServerTests(unittest.TestCase):
 
             self.assertIsNone(_read_session_title(directory, session_id))
 
+    def test_invalid_llm_title_is_not_preserved_as_previous_title(self) -> None:
+        with tempfile.TemporaryDirectory() as d:
+            root = Path(d)
+            _, state = _build_client(root)
+            session_id = 'invalid-llm-title'
+            directory = state.account_paths('alice')['sessions']
+            agent = state.agent_for('alice', session_id)
+
+            _save_in_progress_session(
+                directory=directory,
+                agent=agent,
+                session_id=session_id,
+                prompt='帮我生成一批地图导航测试数据。',
+            )
+            stored = load_agent_session(session_id, directory=directory)
+            save_agent_session(
+                replace(
+                    stored,
+                    session_metadata={
+                        **(stored.session_metadata or {}),
+                        'title': '<think>**Generating short title',
+                        'title_source': 'llm',
+                    },
+                ),
+                directory=directory,
+            )
+
+            self.assertIsNone(_read_session_title(directory, session_id))
+
     def test_session_title_refines_first_message_title_after_run(self) -> None:
         with tempfile.TemporaryDirectory() as d:
             root = Path(d)
@@ -960,6 +990,20 @@ class GuiServerTests(unittest.TestCase):
             self.assertEqual(config.base_url, 'http://model.mify.ai.srv/v1')
             client.complete.assert_called_once()
 
+    def test_clean_session_title_rejects_reasoning_leak(self) -> None:
+        self.assertIsNone(_clean_session_title('<think>**Generating short title'))
+        self.assertIsNone(
+            _clean_session_title(
+                '<think>reasoning</think>\nGenerating short Chinese title'
+            )
+        )
+
+    def test_clean_session_title_strips_markdown_and_prefix(self) -> None:
+        self.assertEqual(
+            _clean_session_title('**标题：地图导航测试数据。**'),
+            '地图导航测试数据',
+        )
+
     def test_clear_runtime_state(self) -> None:
         with tempfile.TemporaryDirectory() as d:
             client, _ = _build_client(Path(d))