diff --git a/entity/ffmpeg.py b/entity/ffmpeg.py
index 9419a3b..62234f5 100644
--- a/entity/ffmpeg.py
+++ b/entity/ffmpeg.py
@@ -56,7 +56,11 @@ class FfmpegTask(object):
         self.input_file.extend(inputs)
 
     def add_overlay(self, *overlays):
-        self.overlays.extend(overlays)
+        for overlay in overlays:
+            if str(overlay).endswith('.ass'):
+                self.subtitles.append(overlay)
+            else:
+                self.overlays.append(overlay)
         self.correct_task_type()
 
     def add_audios(self, *audios):
@@ -139,6 +143,9 @@ class FfmpegTask(object):
                 filter_args.append(f"{video_output_str}[{input_index}:v]scale=rw:rh[v]")
                 filter_args.append(f"[v][{input_index}:v]overlay=1:eof_action=endall[v]")
                 video_output_str = "[v]"
+            for subtitle in self.subtitles:
+                filter_args.append(f"{video_output_str}ass={subtitle}[v]")
+                video_output_str = "[v]"
             output_args.append("-map")
             output_args.append(video_output_str)
             output_args.append("-r")