diff --git a/mybatis-plus-join-core/src/main/java/com/github/yulichang/toolkit/Ref.java b/mybatis-plus-join-core/src/main/java/com/github/yulichang/toolkit/Ref.java
new file mode 100644
index 0000000..a890ca4
--- /dev/null
+++ b/mybatis-plus-join-core/src/main/java/com/github/yulichang/toolkit/Ref.java
@@ -0,0 +1,9 @@
+package com.github.yulichang.toolkit;
+
+/**
+ * @author yulichang
+ * @since 1.4.7.2
+ */
+@SuppressWarnings("unused")
+public class Ref<T> {
+}
diff --git a/mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJAbstractWrapper.java b/mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJAbstractWrapper.java
index 768b9bb..78329a3 100644
--- a/mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJAbstractWrapper.java
+++ b/mybatis-plus-join-core/src/main/java/com/github/yulichang/wrapper/MPJAbstractWrapper.java
@@ -14,6 +14,7 @@ import com.baomidou.mybatisplus.core.toolkit.sql.StringEscape;
 import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
 import com.github.yulichang.toolkit.LambdaUtils;
 import com.github.yulichang.toolkit.MPJSqlInjectionUtils;
+import com.github.yulichang.toolkit.Ref;
 import com.github.yulichang.toolkit.TableList;
 import com.github.yulichang.toolkit.sql.SqlScriptUtils;
 import com.github.yulichang.wrapper.enums.PrefixEnum;
@@ -24,6 +25,8 @@ import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.BiPredicate;
 import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
 
 import static com.baomidou.mybatisplus.core.enums.SqlKeyword.*;
 import static com.baomidou.mybatisplus.core.enums.WrapperKeyword.APPLY;
@@ -141,6 +144,21 @@ public abstract class MPJAbstractWrapper<T, Children extends MPJAbstractWrapper<
         return typedThis;
     }
 
+    /**
+     * 转为子类，方便自定义继承扩展
+     */
+    public <C extends Children> C toChildren(Ref<C> children) {
+        return (C) this;
+    }
+
+    /**
+     * 转为子类，方便自定义继承扩展
+     * 需要子类自定义字段
+     */
+    public <C extends Children> C toChildren(Supplier<C> s) {
+        return (C) this;
+    }
+
     /**
      * 开启检查 SQL 注入
      */