diff --git a/paddlespeech/s2t/exps/u2/bin/test_wav.py b/paddlespeech/s2t/exps/u2/bin/test_wav.py
index a55a1eca0..e01d0e401 100644
--- a/paddlespeech/s2t/exps/u2/bin/test_wav.py
+++ b/paddlespeech/s2t/exps/u2/bin/test_wav.py
@@ -18,7 +18,6 @@ from pathlib import Path
 
 import paddle
 import soundfile
-import numpy as np
 from yacs.config import CfgNode
 
 from paddlespeech.audio.transform.transformation import Transformation