diff --git a/tests/unit/tts/test_pwg.py b/tests/unit/tts/test_pwg.py
index 2eec5caec..10c82c9fd 100644
--- a/tests/unit/tts/test_pwg.py
+++ b/tests/unit/tts/test_pwg.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 import paddle
 import torch
+from paddle.device.cuda import synchronize
 from parallel_wavegan.layers import residual_block
 from parallel_wavegan.layers import upsample
 from parallel_wavegan.models import parallel_wavegan as pwgan
@@ -24,7 +25,6 @@ from paddlespeech.t2s.models.parallel_wavegan import PWGGenerator
 from paddlespeech.t2s.models.parallel_wavegan import ResidualBlock
 from paddlespeech.t2s.models.parallel_wavegan import ResidualPWGDiscriminator
 from paddlespeech.t2s.utils.layer_tools import summary
-from paddle.device.cuda import synchronize
 
 paddle.set_device("gpu:0")
 device = torch.device("cuda:0")