diff --git a/paddle_fl/core/scheduler/agent_master.py b/paddle_fl/core/scheduler/agent_master.py
index d436b822865fe0189bddb1c871b69a20dcdeae17..e9b42a91a256d0ea6c59f8fc8d1b2390b9566aaf 100644
--- a/paddle_fl/core/scheduler/agent_master.py
+++ b/paddle_fl/core/scheduler/agent_master.py
@@ -104,10 +104,7 @@ class FLScheduler(object):
 
     def start_fl_training(self):
         # loop until training is done
-        loop = 0
         while True:
-            if loop <= 1:
-                print(loop)
             random.shuffle(self.fl_workers)
             worker_dict = {}
             for worker in self.fl_workers[:self.sample_worker_num]:
diff --git a/paddle_fl/core/trainer/diffiehellman/diffiehellman.py b/paddle_fl/core/trainer/diffiehellman/diffiehellman.py
index d6010fe970a29846bd7f5033073c7313de80effe..d5e1b196f56e5694b4112a8ff82022ee3bac7910 100644
--- a/paddle_fl/core/trainer/diffiehellman/diffiehellman.py
+++ b/paddle_fl/core/trainer/diffiehellman/diffiehellman.py
@@ -43,8 +43,6 @@ try:
     rng = RAND_bytes
 except(AttributeError, ImportError):
     rng = os.urandom
-    #raise RNGError
-#python2
 
 class DiffieHellman:
     """
diff --git a/paddle_fl/core/trainer/fl_trainer.py b/paddle_fl/core/trainer/fl_trainer.py
index b58ac1c8b74330918f54b331ab3621f98d8b531f..00cb67e72617c7edf73e4714b307090d78493e88 100755
--- a/paddle_fl/core/trainer/fl_trainer.py
+++ b/paddle_fl/core/trainer/fl_trainer.py
@@ -90,12 +90,12 @@ class FLTrainer(object):
         # TODO(guru4elephant): add connection with master
         if self.cur_step != 0:
             while not self.agent.finish_training():
-                print('wait others finish')
+                self._logger.debug("Wait others finish")
                 continue
         while not self.agent.can_join_training():
-            print("wait permit")
+            self._logger.debug("Wait permit")
             continue
-        print("ready to train")
+        self._logger.debug("Ready to train")
         return False
 
 
@@ -124,7 +124,6 @@ class FedAvgTrainer(FLTrainer):
         self.exe.run(self._recv_program)
         epoch = 0
         for i in range(num_epoch):
-                print(epoch)
                 for data in reader():
                     self.exe.run(self._main_program,
                            feed=feeder.feed(data),