diff --git a/paddlespeech/s2t/utils/tensor_utils.py b/paddlespeech/s2t/utils/tensor_utils.py
index 0dbaa0b6b77031d4b8e8aa29fcc9246458b8ab99..e105253c2116f65d4e24508a8cc281d84d7926b3 100644
--- a/paddlespeech/s2t/utils/tensor_utils.py
+++ b/paddlespeech/s2t/utils/tensor_utils.py
@@ -82,7 +82,7 @@ def pad_sequence(sequences: List[paddle.Tensor],
     max_size = sequences[0].size()
     # (TODO Hui Zhang): slice not supprot `end==start`
     # trailing_dims = max_size[1:]
-    trailing_dims = max_size[1:] if max_size.ndim >= 2 else ()
+    trailing_dims = tuple(max_size[1:].numpy().tolist()) if sequences[0].ndim >= 2 else ()
     max_len = max([s.shape[0] for s in sequences])
     if batch_first:
         out_dims = (len(sequences), max_len) + trailing_dims
@@ -99,7 +99,7 @@ def pad_sequence(sequences: List[paddle.Tensor],
         if batch_first:
             # TODO (Hui Zhang): set_value op not supprot `end==start`
             # TODO (Hui Zhang): set_value op not support int16
-            # TODO (Hui Zhang): set_varbase 2 rank not support [0,0,...] 
+            # TODO (Hui Zhang): set_varbase 2 rank not support [0,0,...]
             # out_tensor[i, :length, ...] = tensor
             if length != 0:
                 out_tensor[i, :length] = tensor
@@ -145,7 +145,7 @@ def add_sos_eos(ys_pad: paddle.Tensor, sos: int, eos: int,
                 [ 4,  5,  6, 11, -1, -1],
                 [ 7,  8,  9, 11, -1, -1]])
     """
-    # TODO(Hui Zhang): using comment code, 
+    # TODO(Hui Zhang): using comment code,
     #_sos = paddle.to_tensor(
     #    [sos], dtype=paddle.long, stop_gradient=True, place=ys_pad.place)
     #_eos = paddle.to_tensor(