diff --git a/fleetrec/core/trainers/single_trainer.py b/fleetrec/core/trainers/single_trainer.py
index 56daafe1debd3d3b01e2961ef4249ddcf7cf63b4..c3da7edd9619458b53988f415c8e339256e3d6de 100644
--- a/fleetrec/core/trainers/single_trainer.py
+++ b/fleetrec/core/trainers/single_trainer.py
@@ -64,7 +64,7 @@ class SingleTrainer(TranspileTrainer):
 
         program = fluid.compiler.CompiledProgram(
             fluid.default_main_program()).with_data_parallel(
-            loss_name=self.model.get_cost_op.name)
+            loss_name=self.model.get_cost_op().name)
 
         metrics_varnames = []
         metrics_format = []
diff --git a/fleetrec/demo/ctr-dnn_train.yaml b/fleetrec/demo/ctr-dnn_train.yaml
index 37e1ab222f7d8df456ce5773923226de46d65e43..4d2644e366ed638136fad3767b4035e5ac950c60 100644
--- a/fleetrec/demo/ctr-dnn_train.yaml
+++ b/fleetrec/demo/ctr-dnn_train.yaml
@@ -14,7 +14,7 @@
 
 train:
   trainer:
-    trainer: "fleetrec/demo/user_define_trainer.py"
+    #trainer: "fleetrec/demo/user_define_trainer.py"
     threads: 4
     # for cluster training
     strategy: "async"
diff --git a/fleetrec/models/ctr/dnn/model.py b/fleetrec/models/ctr/dnn/model.py
index ac3887d70c9578892f2ebb5b4796d632685a5327..a4e6cf6868ccac57e457c9c58cab2b8ee2310d94 100644
--- a/fleetrec/models/ctr/dnn/model.py
+++ b/fleetrec/models/ctr/dnn/model.py
@@ -57,9 +57,9 @@ class Model(ModelBase):
             self._data_var.append(input)
 
         self._data_var.append(self.label_input)
-        
+
         if self._platform != "LINUX":
-            self._data_loader = fluid.io.PyReader(
+            self._data_loader = fluid.io.DataLoader.from_generator(
                 feed_list=self._data_var, capacity=64, use_double_buffer=False, iterable=False)
 
     def net(self):