diff --git a/sanguo_api/routes.py b/sanguo_api/routes.py
index 0da44c9..3ac3d91 100644
--- a/sanguo_api/routes.py
+++ b/sanguo_api/routes.py
@@ -329,18 +329,24 @@ def optimization_results(task_id: str):
 # ===== Task 4: Backtest result API extensions =====
 
 def _get_metrics_file_path(task_id: str) -> str | None:
-    """Get the metrics file path. Resolves the request task_id to the result's
-    internal task_id first — run_cta_backtest writes {task_id}_metrics.json under
-    ITS OWN uuid task_id (result.task_id), which differs from the runner's task_id."""
+    """Get the metrics file path. Tries the request task_id directly first, then
+    falls back to the result's internal task_id — run_cta_backtest writes the file
+    under ITS OWN uuid task_id (result.task_id), which differs from the runner's
+    task_id when submitted via the API."""
     orch = get_orchestrator()
-    r = orch.get_result(task_id)
-    if r is None or not getattr(r, "task_id", None):
+    if not (hasattr(orch, 'db_path') and orch.db_path):
         return None
-    if hasattr(orch, 'db_path') and orch.db_path:
-        file_dir = os.path.dirname(os.path.abspath(orch.db_path))
-        metrics_file = os.path.join(file_dir, f"{r.task_id}_metrics.json")
-        if os.path.exists(metrics_file):
-            return metrics_file
+    file_dir = os.path.dirname(os.path.abspath(orch.db_path))
+    # 1. direct lookup by request task_id
+    direct = os.path.join(file_dir, f"{task_id}_metrics.json")
+    if os.path.exists(direct):
+        return direct
+    # 2. resolve via result.task_id (run_cta_backtest's own uuid)
+    r = orch.get_result(task_id)
+    if r is not None and getattr(r, "task_id", None):
+        resolved = os.path.join(file_dir, f"{r.task_id}_metrics.json")
+        if os.path.exists(resolved):
+            return resolved
     return None