diff --git a/auto_merge_video.py b/auto_merge_video.py
index aab98e8..fe655dc 100644
--- a/auto_merge_video.py
+++ b/auto_merge_video.py
@@ -10,7 +10,7 @@ template_video_part = {
     "start": "",
     "end": "",
     "part_start": "",
-    "duration": "",
+    "_duration_str": "",
 }
 template_current_video = {
     "parts": [],
@@ -31,15 +31,15 @@ def merge_video_parts_and_split(video):
     for part in video["parts"]:
         if part["part_start"] is None:
             raise Exception("视频片段part_start读取异常")
-        if prev_part["duration"] == "":
+        if prev_part["_duration_str"] == "":
             duration = float(part["part_start"]) - float(prev_part["part_start"])
             if duration <= 60:
                 raise Exception("视频片段duration过小")
-            prev_part["duration"] = str(duration)
+            prev_part["_duration_str"] = str(duration)
         new_filename = str(time.time())
         os.system(" ".join([
             "ffmpeg", "-y", "-i", "\"{filename}.{file_ext}\"".format_map(prev_part),
-            "-c copy", "-f mpegts", "-t {duration}".format_map(prev_part),
+            "-c copy", "-f mpegts", "-t {_duration_str}".format_map(prev_part),
             "\"{}.ts\"".format(new_filename)
         ]))
         os.system(" ".join([