diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnBE.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnBE.java
index d133eac32baddb..810d281ac579ac 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnBE.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rules/FoldConstantRuleOnBE.java
@@ -176,7 +176,16 @@ private static Expression replace(
             if (newChild != child) {
                 hasNewChildren = true;
             }
-            newChildren.add(newChild);
+            if (!newChild.getDataType().equals(child.getDataType())) {
+                try {
+                    newChildren.add(newChild.castTo(child.getDataType()));
+                } catch (Exception e) {
+                    LOG.warn("expression of type {} cast to {} failed. ", newChild.getDataType(), child.getDataType());
+                    newChildren.add(newChild);
+                }
+            } else {
+                newChildren.add(newChild);
+            }
         }
         return hasNewChildren ? root.withChildren(newChildren) : root;
     }
diff --git a/regression-test/suites/nereids_p0/expression/fold_constant/fold_constant_by_be.groovy b/regression-test/suites/nereids_p0/expression/fold_constant/fold_constant_by_be.groovy
index 809b8e8b291d23..668e88c6f04944 100644
--- a/regression-test/suites/nereids_p0/expression/fold_constant/fold_constant_by_be.groovy
+++ b/regression-test/suites/nereids_p0/expression/fold_constant/fold_constant_by_be.groovy
@@ -53,4 +53,9 @@ suite("fold_constant_by_be") {
 
     sql 'set query_timeout=12;'
     qt_sql "select sleep(sign(1)*5);"
+    
+    explain {
+        sql("verbose select substring('123456', 1, 3)")
+        contains "varchar(3)"
+    }
 }