diff --git a/workflow/video.py b/workflow/video.py
index 5b352b8..c248db8 100644
--- a/workflow/video.py
+++ b/workflow/video.py
@@ -213,6 +213,7 @@ def quick_split_video(file):
             "{}.mp4".format(current_dt)
         ], stdout=subprocess.PIPE)
         handle_ffmpeg_output(split_process.stdout)
+        split_process.wait()
         current_sec += VIDEO_CLIP_EACH_SEC
 
 
diff --git a/workflow/worker.py b/workflow/worker.py
index 34f66be..94fa135 100644
--- a/workflow/worker.py
+++ b/workflow/worker.py
@@ -31,7 +31,9 @@ def do_workflow(video_file, danmaku_base_file, *danmaku_files):
         quick_split_video(filename)
     # clean files
     for filename in file_need_split:
-        os.remove(filename)
+        if os.path.isfile(filename):
+            os.remove(filename)
     for file in result:
-        os.remove(file)
+        if os.path.isfile(file):
+            os.remove(file)