diff --git a/demo/dygraph/pruning/eval.py b/demo/dygraph/pruning/eval.py
index 37024f35636f6cc67b38564ace43f87964c3a398..486820741bf794688bdf26a1ceefa55186f5c4c3 100644
--- a/demo/dygraph/pruning/eval.py
+++ b/demo/dygraph/pruning/eval.py
@@ -105,7 +105,7 @@ def eval(args):
     ratios = {}
     for param in params:
         ratios[param] = args.pruned_ratio
-    print(f"ratios: {ratios}")
+    print("ratios: {}".format(ratios))
     pruner.prune_vars(ratios, [0])
 
     model = paddle.Model(net, inputs, labels)
diff --git a/demo/dygraph/pruning/export_model.py b/demo/dygraph/pruning/export_model.py
index 99f6afdb827150dc812c1d5fdd1db48c7a137c22..2724276cefe4c7a3f4b3f45944cc767bd1839b23 100644
--- a/demo/dygraph/pruning/export_model.py
+++ b/demo/dygraph/pruning/export_model.py
@@ -86,7 +86,7 @@ def export(args):
     ratios = {}
     for param in params:
         ratios[param] = args.pruned_ratio
-    print(f"ratios: {ratios}")
+    print("ratios: {}".format(ratios))
     pruner.prune_vars(ratios, [0])
 
     param_state_dict = paddle.load(args.checkpoint + ".pdparams")
diff --git a/demo/dygraph/pruning/train.py b/demo/dygraph/pruning/train.py
index 64a936667e1d8c1a9b023ae792dae1f5746fcb82..70ad3ddab9f8986151de36fc1cee2df141654585 100644
--- a/demo/dygraph/pruning/train.py
+++ b/demo/dygraph/pruning/train.py
@@ -171,7 +171,7 @@ def compress(args):
 
     for param in net.parameters():
         if "conv2d" in param.name:
-            print(f"{param.name}\t{param.shape}")
+            print("{}\t{}".format(param.name, param.shape))
 
     net.train()
     model = paddle.Model(net, inputs, labels)