diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/export.py b/paddlespeech/s2t/exps/deepspeech2/bin/export.py
index ae43bf82cb6b258ac87ee55221e94421d7b203d1..f1b84969d84195f424e72e95b7cb76a9b500d682 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/export.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/export.py
@@ -40,7 +40,7 @@ if __name__ == "__main__":
     parser.add_argument(
         '--nxpu',
         type=int,
-        default=1,
+        default=0,
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     args = parser.parse_args()
     print("model_type:{}".format(args.model_type))
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test.py b/paddlespeech/s2t/exps/deepspeech2/bin/test.py
index f29f508326100d1d66312754fa1eee8cbacee844..c91be411a38a5bdae1031d9890541987cdedfef7 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test.py
@@ -40,7 +40,7 @@ if __name__ == "__main__":
     parser.add_argument(
         '--nxpu',
         type=int,
-        default=1,
+        default=0,
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     args = parser.parse_args()
     print_arguments(args, globals())
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py b/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
index c136ddf29f317c00409125cdcbc7c7a970a7095e..923c3db49b2db0db5e2678ce672841694c4a912e 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
@@ -43,7 +43,7 @@ if __name__ == "__main__":
     parser.add_argument(
         '--nxpu',
         type=int,
-        default=1,
+        default=0,
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     parser.add_argument(
         "--enable-auto-log", action="store_true", help="use auto log")
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/train.py b/paddlespeech/s2t/exps/deepspeech2/bin/train.py
index cb4867ef25c03e4a1ccb4bb52547be9e10114a82..d80cd0cb29b4ec82e0b81c88be875679b6aa8e77 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/train.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/train.py
@@ -36,7 +36,7 @@ if __name__ == "__main__":
     parser.add_argument(
         '--nxpu',
         type=int,
-        default=1,
+        default=0,
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     args = parser.parse_args()
     print("model_type:{}".format(args.model_type))
diff --git a/paddlespeech/s2t/training/trainer.py b/paddlespeech/s2t/training/trainer.py
index d30556ca1bdf9ea375743fdc051b646944297b26..a7eb9892deff7e06c7109d304eaf457d3f06ddda 100644
--- a/paddlespeech/s2t/training/trainer.py
+++ b/paddlespeech/s2t/training/trainer.py
@@ -119,6 +119,9 @@ class Trainer():
                 paddle.set_device('xpu')
         elif self.args.ngpu > 0:
             paddle.set_device("gpu")
+        else:
+            raise Exception("invalid device")
+
         if self.parallel:
             self.init_parallel()