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 1739c147d8678d..40c06b76036c17 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
@@ -109,7 +109,16 @@ private Expression replace(Expression root, Map<String, Expression> constMap, Ma
             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 e1162c662b9124..2a59de195a635e 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
@@ -40,4 +40,9 @@ suite("fold_constant_by_be") {
     sql """ INSERT INTO str_tb VALUES (2, repeat("test1111", 10000)); """
 
     qt_sql_1 """ select length(v1) from str_tb; """
-}
\ No newline at end of file
+    
+    explain {
+        sql("verbose select substring('123456', 1, 3)")
+        contains "varchar(3)"
+    }
+}