diff --git a/biz/ffmpeg.py b/biz/ffmpeg.py
index 246a382..0fdd6d6 100644
--- a/biz/ffmpeg.py
+++ b/biz/ffmpeg.py
@@ -132,7 +132,7 @@ def clear_task_tmp_file(ffmpeg_task):
     for task in ffmpeg_task.analyze_input_render_tasks():
         clear_task_tmp_file(task)
     try:
-        if "template" not in ffmpeg_task.get_output_file():
+        if os.getenv("TEMPLATE_DIR") not in ffmpeg_task.get_output_file():
             os.remove(ffmpeg_task.get_output_file())
             logger.info("delete tmp file: " + ffmpeg_task.get_output_file())
         else: