diff --git a/dygraph/infer.py b/dygraph/infer.py
index 1cc15d319f09e86693eb35006fd6d7efc3f5becc..f5caf7a435d3083f7d84106024096684a9d4f3b8 100644
--- a/dygraph/infer.py
+++ b/dygraph/infer.py
@@ -37,12 +37,8 @@ def parse_args():
     parser.add_argument(
         '--model_name',
         dest='model_name',
-        help=
-        'Model type for testing, which is one of ("UNet", "HRNet_W18_Small_V1", "HRNet_W18_Small_V2", '
-        '"HRNet_W18", "HRNet_W30", "HRNet_W32", "HRNet_W40", "HRNet_W44", "HRNet_W48", '
-        '"HRNet_W60", "HRNet_W64", "SE_HRNet_W18_Small_V1", "SE_HRNet_W18_Small_V2", "SE_HRNet_W18", '
-        '"SE_HRNet_W30", "SE_HRNet_W32", "SE_HRNet_W40","SE_HRNet_W44", "SE_HRNet_W48", '
-        '"SE_HRNet_W60", "SE_HRNet_W64")',
+        help='Model type for testing, which is one of {}'.format(
+            str(list(MODELS.keys()))),
         type=str,
         default='UNet')
 
diff --git a/dygraph/models/hrnet.py b/dygraph/models/hrnet.py
index fac8a929be40acce2d801c3cdbbe89bb634bead3..bccc303bb435e48554991a21b4fd72dd90a3cb37 100644
--- a/dygraph/models/hrnet.py
+++ b/dygraph/models/hrnet.py
@@ -18,7 +18,8 @@ import paddle
 import paddle.fluid as fluid
 from paddle.fluid.param_attr import ParamAttr
 from paddle.fluid.layer_helper import LayerHelper
-from paddle.fluid.dygraph.nn import Conv2D, Pool2D, BatchNorm, Linear
+from paddle.fluid.dygraph.nn import Conv2D, Pool2D, Linear
+from paddle.fluid.dygraph import SyncBatchNorm as BatchNorm
 
 __all__ = [
     "HRNet_W18_Small_V1", "HRNet_W18_Small_V2", "HRNet_W18", "HRNet_W30",
diff --git a/dygraph/train.py b/dygraph/train.py
index 8573591e25f2964610bd3da33b224c52bcfe1da9..709a66bb8c7f55dac0a83e5435a42893eb4d2e9a 100644
--- a/dygraph/train.py
+++ b/dygraph/train.py
@@ -38,12 +38,8 @@ def parse_args():
     parser.add_argument(
         '--model_name',
         dest='model_name',
-        help=
-        'Model type for training, which is one of ("UNet", "HRNet_W18_Small_V1", "HRNet_W18_Small_V2", '
-        '"HRNet_W18", "HRNet_W30", "HRNet_W32", "HRNet_W40", "HRNet_W44", "HRNet_W48", '
-        '"HRNet_W60", "HRNet_W64", "SE_HRNet_W18_Small_V1", "SE_HRNet_W18_Small_V2", "SE_HRNet_W18", '
-        '"SE_HRNet_W30", "SE_HRNet_W32", "SE_HRNet_W40","SE_HRNet_W44", "SE_HRNet_W48", '
-        '"SE_HRNet_W60", "SE_HRNet_W64")',
+        help='Model type for training, which is one of {}'.format(
+            str(list(MODELS.keys()))),
         type=str,
         default='UNet')
 
@@ -186,6 +182,7 @@ def train(model,
     total_steps = steps_per_epoch * (num_epochs - start_epoch)
     num_steps = 0
     best_mean_iou = -1.0
+    best_model_epoch = -1
     for epoch in range(start_epoch, num_epochs):
         for step, data in enumerate(loader):
             images = data[0]
@@ -245,9 +242,9 @@ def train(model,
                     best_model_dir = os.path.join(save_dir, "best_model")
                     fluid.save_dygraph(model.state_dict(),
                                        os.path.join(best_model_dir, 'model'))
-                    logging.info(
-                        'Current evaluated best model in eval_dataset is epoch_{}, miou={:4f}'
-                        .format(best_model_epoch, best_mean_iou))
+                logging.info(
+                    'Current evaluated best model in eval_dataset is epoch_{}, miou={:4f}'
+                    .format(best_model_epoch, best_mean_iou))
 
                 if use_vdl:
                     log_writer.add_scalar('Evaluate/mean_iou', mean_iou,
diff --git a/dygraph/val.py b/dygraph/val.py
index 36d4242966f0e98e381130c533d67c46b31aefe1..41d0d33485d1052bef3b1c4d70b546cdf89d3922 100644
--- a/dygraph/val.py
+++ b/dygraph/val.py
@@ -39,12 +39,8 @@ def parse_args():
     parser.add_argument(
         '--model_name',
         dest='model_name',
-        help=
-        'Model type for evaluation, which is one of ("UNet", "HRNet_W18_Small_V1", "HRNet_W18_Small_V2", '
-        '"HRNet_W18", "HRNet_W30", "HRNet_W32", "HRNet_W40", "HRNet_W44", "HRNet_W48", '
-        '"HRNet_W60", "HRNet_W64", "SE_HRNet_W18_Small_V1", "SE_HRNet_W18_Small_V2", "SE_HRNet_W18", '
-        '"SE_HRNet_W30", "SE_HRNet_W32", "SE_HRNet_W40","SE_HRNet_W44", "SE_HRNet_W48", '
-        '"SE_HRNet_W60", "SE_HRNet_W64")',
+        help='Model type for evaluation, which is one of {}'.format(
+            str(list(MODELS.keys()))),
         type=str,
         default='UNet')