diff --git a/web_server.py b/web_server.py
index 2113afb..32ab5ff 100644
--- a/web_server.py
+++ b/web_server.py
@@ -686,7 +686,19 @@ def get_user_resources(username: Optional[str] = None) -> Tuple[Optional[WebTerm
         run_mode = session.get('run_mode')
         thinking_mode_flag = session.get('thinking_mode')
         if run_mode not in {"fast", "thinking", "deep"}:
-            if thinking_mode_flag:
+            preferred_run_mode = None
+            try:
+                personal_config = load_personalization_config(workspace.data_dir)
+                candidate_mode = (personal_config or {}).get('default_run_mode')
+                if isinstance(candidate_mode, str) and candidate_mode.lower() in {"fast", "thinking", "deep"}:
+                    preferred_run_mode = candidate_mode.lower()
+            except Exception as exc:
+                debug_log(f"[UserInit] 加载个性化偏好失败: {exc}")
+
+            if preferred_run_mode:
+                run_mode = preferred_run_mode
+                thinking_mode_flag = preferred_run_mode != "fast"
+            elif thinking_mode_flag:
                 run_mode = "deep"
             else:
                 run_mode = "fast"