diff --git a/paddle/function/CrossMapNormalOp.cpp b/paddle/function/CrossMapNormalOp.cpp
index 92980c503fdaaaa9ac600070197dba6ba4bfb7a4..8e7dc72524a7680a03ea6eb4770a3e25c09ad913 100644
--- a/paddle/function/CrossMapNormalOp.cpp
+++ b/paddle/function/CrossMapNormalOp.cpp
@@ -188,8 +188,13 @@ public:
     CHECK(inputs[0].shape() == inputs[3].shape());
     CHECK(inputs[0].shape() == outputs[0].shape());
 
-    // TODO(hedaoyuan): need support ASSIGN_TO mode.
-    CHECK_EQ(outputs[0].getArgType(), ADD_TO);
+    if (outputs[0].getArgType() != ADD_TO) {
+      // Currently, some algorithm implementations are ASSIGN_TO mode,
+      // if need to support the ADD_TO calculation, need to clear the output.
+      typename Tensor<real, Device>::Vector tmp(
+          outputs[0].shape().getElements(), outputs[0].data<real>());
+      tmp.zero();
+    }
 
     size_t samples = inputs[0].shape()[0];
     size_t channels = inputs[0].shape()[1];
diff --git a/paddle/function/CrossMapNormalOpTest.cpp b/paddle/function/CrossMapNormalOpTest.cpp
index da196a699cc32b079f8e04c65ec6b25b7dc24700..51f5da81bfc9ae870ac9949ba74da01a9449a04d 100644
--- a/paddle/function/CrossMapNormalOpTest.cpp
+++ b/paddle/function/CrossMapNormalOpTest.cpp
@@ -47,9 +47,6 @@ TEST(CrossMapNormal, real) {
   }
 }
 
-#if 0
-// TODO(hedaoyuan): Now CrossMapNormalGrad not support ASSIGN_TO mode.
-// Maybe all Function need support ASSIGN_TO mode.
 TEST(CrossMapNormalGrad, real) {
   for (size_t numSamples : {5, 32}) {
     for (size_t channels : {1, 5, 32}) {
@@ -79,6 +76,5 @@ TEST(CrossMapNormalGrad, real) {
     }
   }
 }
-#endif
 
 }  // namespace paddle