diff --git a/modules/memory_debug.py b/modules/memory_debug.py
index 310689a..0788b85 100644
--- a/modules/memory_debug.py
+++ b/modules/memory_debug.py
@@ -17,6 +17,7 @@ from __future__ import annotations
 
 import json
 import os
+import sys
 import threading
 import time
 import tracemalloc
@@ -55,7 +56,10 @@ def _current_rss_mb() -> Optional[float]:
     try:
         import resource
         usage = resource.getrusage(resource.RUSAGE_SELF)
-        return usage.ru_maxrss / 1024.0  # macOS 返回 KB，Linux 返回 KB
+        # macOS: ru_maxrss 单位是 bytes；Linux: 单位是 KB
+        if sys.platform == "darwin":
+            return usage.ru_maxrss / (1024 * 1024)
+        return usage.ru_maxrss / 1024.0
     except Exception:
         pass
     try: