diff --git a/tools/cfg/copy_proto_python_file.py b/tools/cfg/copy_proto_python_file.py
index 133b8cac87f1b764fa34842847e27159e6a61311..b81df4659f772239dffe9a0c414bcb6e15e69ab6 100644
--- a/tools/cfg/copy_proto_python_file.py
+++ b/tools/cfg/copy_proto_python_file.py
@@ -21,13 +21,14 @@ def copy_proto_files(src_proto_files, of_proto_python_dir, dst_proto_python_dir)
 
         if not os.path.exists(dst_file_dir):
             if dst_file_dir:
-                os.makedirs(dst_file_dir)
+                # use parameter exist_ok to avoid misjudgment under multithreading
+                os.makedirs(dst_file_dir, exist_ok=True)
 
-        if not os.path.exists(dst_file):
+        if (
+            not os.path.exists(dst_file)
+            or os.stat(src_file).st_mtime - os.stat(dst_file).st_mtime > 0
+        ):
             copyfile(src_file, dst_file)
-        else:
-            if os.stat(src_file).st_mtime - os.stat(dst_file).st_mtime > 0:
-                copyfile(src_file, dst_file)
 
 
 def main():