diff --git a/Sources/PlayerRecorder.swift b/Sources/PlayerRecorder.swift
index a66840e..7ae1b93 100644
--- a/Sources/PlayerRecorder.swift
+++ b/Sources/PlayerRecorder.swift
@@ -356,17 +356,18 @@ final class PlayerRecorder: NSObject {
             return
         }
         
-        // 创建 AudioMix — 用 kCMPersistentTrackID_Invalid 匹配所有音频轨道
-        // HLS 流在 variant 切换时 audio track ID 会变，绑定具体 ID 会导致 tap 失效
+        // 创建 AudioMix — 必须用实际 trackID
+        // kCMPersistentTrackID_Invalid (=0) 实测不会触发 tap
         let inputParams = AVMutableAudioMixInputParameters()
-        inputParams.trackID = kCMPersistentTrackID_Invalid
+        inputParams.trackID = audioTrack.trackID
         inputParams.audioTapProcessor = tapRef
         
         let audioMix = AVMutableAudioMix()
         audioMix.inputParameters = [inputParams]
         
         playerItem.audioMix = audioMix
-        NSLog("[Recorder] ✓ Audio tap installed on playerItem, trackID=%d", audioTrack.trackID)
+        NSLog("[Recorder] ✓ Audio tap installed: trackID=%d, asset tracks=%d, playerItem.audioMix set",
+              audioTrack.trackID, playerItem.asset.tracks.count)
     }
     
     // MARK: - 开始录制