diff --git a/core/web_terminal.py b/core/web_terminal.py
index b9998b0..47d0cd9 100644
--- a/core/web_terminal.py
+++ b/core/web_terminal.py
@@ -130,13 +130,14 @@ class WebTerminal(MainTerminal):
                 logger.warning("忽略无效默认模型 %s: %s", preferred_model, exc)
 
             preferred_mode = prefs.get("default_run_mode")
-            preferred_permission_mode = None
-            try:
-                preferred_permission_mode = self.get_permission_mode()
-            except Exception:
-                preferred_permission_mode = None
+            preferred_permission_mode = prefs.get("default_permission_mode") or None
+            if preferred_permission_mode not in ("readonly", "approval", "auto_approval", "unrestricted"):
+                try:
+                    preferred_permission_mode = self.get_permission_mode()
+                except Exception:
+                    preferred_permission_mode = None
             if not isinstance(preferred_permission_mode, str) or not preferred_permission_mode.strip():
-                preferred_permission_mode = prefs.get("default_permission_mode") or "unrestricted"
+                preferred_permission_mode = "unrestricted"
             if isinstance(preferred_mode, str) and preferred_mode.lower() in {"fast", "thinking", "deep"}:
                 try:
                     self.set_run_mode(preferred_mode.lower())
diff --git a/server/conversation.py b/server/conversation.py
index 9cc9429..34b54ec 100644
--- a/server/conversation.py
+++ b/server/conversation.py
@@ -482,6 +482,9 @@ def create_conversation(terminal: WebTerminal, workspace: UserWorkspace, usernam
                 safe_run_mode = candidate if candidate in {"fast", "thinking", "deep"} else "fast"
             safe_thinking = bool(thinking_mode) if thinking_mode is not None else safe_run_mode != "fast"
             previous_cm_current = getattr(cm, "current_conversation_id", None)
+            default_permission_mode = (prefs or {}).get("default_permission_mode")
+            if default_permission_mode not in ("readonly", "approval", "auto_approval", "unrestricted"):
+                default_permission_mode = None
             conversation_id = cm.create_conversation(
                 project_path=str(workspace.project_path),
                 thinking_mode=safe_thinking,
@@ -489,7 +492,7 @@ def create_conversation(terminal: WebTerminal, workspace: UserWorkspace, usernam
                 initial_messages=[],
                 model_key=(prefs or {}).get("default_model") or getattr(terminal, "model_key", None),
                 metadata_overrides={
-                    "permission_mode": getattr(terminal, "get_permission_mode", lambda: "unrestricted")(),
+                    "permission_mode": default_permission_mode or getattr(terminal, "get_permission_mode", lambda: "unrestricted")(),
                     "execution_mode": getattr(terminal, "get_execution_mode", lambda: "sandbox")(),
                 },
             )