diff --git a/app/services/generate_video.py b/app/services/generate_video.py
index 8395aef..9b77a2c 100644
--- a/app/services/generate_video.py
+++ b/app/services/generate_video.py
@@ -137,8 +137,12 @@ def merge_materials(
             try:
                 original_audio = video_clip.audio
                 if original_audio:
-                    original_audio = original_audio.with_effects([afx.MultiplyVolume(original_audio_volume)])
-                    logger.info(f"已提取视频原声，音量设置为: {original_audio_volume}")
+                    # 关键修复：只有当音量不为1.0时才进行音量调整，保持原声音量不变
+                    if abs(original_audio_volume - 1.0) > 0.001:  # 使用小的容差值比较浮点数
+                        original_audio = original_audio.with_effects([afx.MultiplyVolume(original_audio_volume)])
+                        logger.info(f"已提取视频原声，音量调整为: {original_audio_volume}")
+                    else:
+                        logger.info("已提取视频原声，保持原始音量不变")
                 else:
                     logger.warning("视频没有音轨，无法提取原声")
             except Exception as e:
diff --git a/app/services/merger_video.py b/app/services/merger_video.py
index c00cbc9..c6ef84d 100644
--- a/app/services/merger_video.py
+++ b/app/services/merger_video.py
@@ -566,9 +566,14 @@ def combine_clip_videos(
             with open(filter_script, 'w') as f:
                 f.write(f"[0:a]volume=0.0[silence];\n")  # 首先静音背景轨道
 
-                # 添加每个音频文件
+                # 添加每个音频文件，并补偿amix的音量稀释
+                # amix会将n个输入的音量平均分配，所以我们需要将每个输入的音量提高n倍来保持原始音量
+                num_inputs = len(audio_timings) + 1  # +1 for silence track
+                volume_compensation = num_inputs  # 补偿系数
+
                 for i, timing in enumerate(audio_timings):
-                    f.write(f"[{i+1}:a]adelay={int(timing['start']*1000)}|{int(timing['start']*1000)}[a{i}];\n")
+                    # 为每个音频添加音量补偿，确保原声保持原始音量
+                    f.write(f"[{i+1}:a]volume={volume_compensation},adelay={int(timing['start']*1000)}|{int(timing['start']*1000)}[a{i}];\n")
 
                 # 混合所有音频
                 mix_str = "[silence]"
diff --git a/app/services/task.py b/app/services/task.py
index 6150247..bec38be 100644
--- a/app/services/task.py
+++ b/app/services/task.py
@@ -197,10 +197,20 @@ def start_subclip(task_id: str, params: VideoClipParams, subclip_path_videos: di
     # 获取优化的音量配置
     optimized_volumes = get_recommended_volumes_for_content('mixed')
 
+    # 检查是否有OST=1的原声片段，如果有，则保持原声音量为1.0不变
+    has_original_audio_segments = any(segment['OST'] == 1 for segment in list_script)
+
     # 应用用户设置和优化建议的组合
     # 如果用户设置了非默认值，优先使用用户设置
     final_tts_volume = params.tts_volume if hasattr(params, 'tts_volume') and params.tts_volume != 1.0 else optimized_volumes['tts_volume']
-    final_original_volume = params.original_volume if hasattr(params, 'original_volume') and params.original_volume != 0.7 else optimized_volumes['original_volume']
+
+    # 关键修复：如果有原声片段，保持原声音量为1.0，确保与原视频音量一致
+    if has_original_audio_segments:
+        final_original_volume = 1.0  # 保持原声音量不变
+        logger.info("检测到原声片段，原声音量设置为1.0以保持与原视频一致")
+    else:
+        final_original_volume = params.original_volume if hasattr(params, 'original_volume') and params.original_volume != 0.7 else optimized_volumes['original_volume']
+
     final_bgm_volume = params.bgm_volume if hasattr(params, 'bgm_volume') and params.bgm_volume != 0.3 else optimized_volumes['bgm_volume']
 
     logger.info(f"音量配置 - TTS: {final_tts_volume}, 原声: {final_original_volume}, BGM: {final_bgm_volume}")
@@ -391,9 +401,19 @@ def start_subclip_unified(task_id: str, params: VideoClipParams):
     # 获取优化的音量配置
     optimized_volumes = get_recommended_volumes_for_content('mixed')
 
+    # 检查是否有OST=1的原声片段，如果有，则保持原声音量为1.0不变
+    has_original_audio_segments = any(segment['OST'] == 1 for segment in list_script)
+
     # 应用用户设置和优化建议的组合
     final_tts_volume = params.tts_volume if hasattr(params, 'tts_volume') and params.tts_volume != 1.0 else optimized_volumes['tts_volume']
-    final_original_volume = params.original_volume if hasattr(params, 'original_volume') and params.original_volume != 0.7 else optimized_volumes['original_volume']
+
+    # 关键修复：如果有原声片段，保持原声音量为1.0，确保与原视频音量一致
+    if has_original_audio_segments:
+        final_original_volume = 1.0  # 保持原声音量不变
+        logger.info("检测到原声片段，原声音量设置为1.0以保持与原视频一致")
+    else:
+        final_original_volume = params.original_volume if hasattr(params, 'original_volume') and params.original_volume != 0.7 else optimized_volumes['original_volume']
+
     final_bgm_volume = params.bgm_volume if hasattr(params, 'bgm_volume') and params.bgm_volume != 0.3 else optimized_volumes['bgm_volume']
 
     logger.info(f"音量配置 - TTS: {final_tts_volume}, 原声: {final_original_volume}, BGM: {final_bgm_volume}")