diff --git a/examples/aishell/asr1/conf/chunk_conformer.yaml b/examples/aishell/asr1/conf/chunk_conformer.yaml
index 68e852ba77770cd0de9b4c33e93ee3ed777fe674..1ad77f97e983e840b7941e12fd6ccdc5330b7ba5 100644
--- a/examples/aishell/asr1/conf/chunk_conformer.yaml
+++ b/examples/aishell/asr1/conf/chunk_conformer.yaml
@@ -70,7 +70,7 @@ batch_bins: 0
 batch_frames_in: 0
 batch_frames_out: 0
 batch_frames_inout: 0
-num_workers: 0
+num_workers: 2
 subsampling_factor: 1
 num_encs: 1
 
@@ -80,6 +80,7 @@ num_encs: 1
 n_epoch: 240 
 accum_grad: 2
 global_grad_clip: 5.0
+dist_sampler: True
 optim: adam
 optim_conf:
   lr: 0.002
diff --git a/examples/aishell/asr1/conf/conformer.yaml b/examples/aishell/asr1/conf/conformer.yaml
index 679a5bf6613d9f360e8aae3e81926e9743612bd2..d5d883a031fafd05c99e7aa3f0b11474f95862d5 100644
--- a/examples/aishell/asr1/conf/conformer.yaml
+++ b/examples/aishell/asr1/conf/conformer.yaml
@@ -76,6 +76,7 @@ num_encs: 1
 n_epoch: 240 
 accum_grad: 2
 global_grad_clip: 5.0
+dist_sampler: True
 optim: adam
 optim_conf:
   lr: 0.002
@@ -84,7 +85,7 @@ scheduler: warmuplr
 scheduler_conf:
   warmup_steps: 25000
   lr_decay: 1.0
-log_interval: 100
+log_interval: 1
 checkpoint:
   kbest_n: 50
   latest_n: 5
diff --git a/examples/aishell/asr1/conf/transformer.yaml b/examples/aishell/asr1/conf/transformer.yaml
index 9d2946537b44ed55f59dbebc09de2ef7571324bf..9e08ea0ec79168fb969cb3b13a54be60e94157af 100644
--- a/examples/aishell/asr1/conf/transformer.yaml
+++ b/examples/aishell/asr1/conf/transformer.yaml
@@ -61,16 +61,17 @@ batch_frames_in: 0
 batch_frames_out: 0
 batch_frames_inout: 0
 preprocess_config: conf/preprocess.yaml 
-num_workers: 0
+num_workers: 2
 subsampling_factor: 1
 num_encs: 1
 
 ###########################################
 #                 Training                #
 ###########################################
-n_epoch: 240 
+n_epoch: 30
 accum_grad: 2
 global_grad_clip: 5.0
+dist_sampler: False
 optim: adam
 optim_conf:
   lr: 0.002
diff --git a/paddlespeech/s2t/models/u2/u2.py b/paddlespeech/s2t/models/u2/u2.py
index e94a127db60cfcd340350b23dd890195bdb729d1..51388586f97edc74ac8c91f264d4146b15a5125c 100644
--- a/paddlespeech/s2t/models/u2/u2.py
+++ b/paddlespeech/s2t/models/u2/u2.py
@@ -51,7 +51,6 @@ from paddlespeech.s2t.utils.tensor_utils import pad_sequence
 from paddlespeech.s2t.utils.tensor_utils import th_accuracy
 from paddlespeech.s2t.utils.utility import log_add
 from paddlespeech.s2t.utils.utility import UpdateConfig
-# from paddlespeech.s2t.modules.initializer import initialize
 
 __all__ = ["U2Model", "U2InferModel"]