diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/datasource/FlexDataSource.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/datasource/FlexDataSource.java
index bec05aaa..b36879b7 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/datasource/FlexDataSource.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/datasource/FlexDataSource.java
@@ -28,7 +28,6 @@ import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 import java.sql.Connection;
 import java.sql.SQLException;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
@@ -154,7 +153,6 @@ public class FlexDataSource extends AbstractDataSource {
                 //do nothing
                 return null;
             }
-            System.out.println(">>>>>>invoke: " + method.getName() + "   args: " + Arrays.toString(args));
             return method.invoke(original, args);
         }
 
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/Db.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/Db.java
index 6235cba0..42466663 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/Db.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/Db.java
@@ -26,7 +26,6 @@ import org.apache.ibatis.util.MapUtil;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
-import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Supplier;
 
@@ -395,34 +394,29 @@ public class Db {
 
     public static boolean tx(Supplier<Boolean> supplier) {
         //上一级事务的id，支持事务嵌套
-        String prevXID = TransactionContext.getXID();
+        String higherXID = TransactionContext.getXID();
         try {
-            String xid = UUID.randomUUID().toString();
-            TransactionContext.hold(xid);
+            String xid = TransactionalManager.startTransactional();
             Boolean success = false;
             boolean rollbacked = false;
             try {
                 success = supplier.get();
             } catch (Exception e) {
                 rollbacked = true;
-                TransactionContext.release();
                 TransactionalManager.rollback(xid);
                 e.printStackTrace();
             } finally {
                 if (success != null && success) {
-                    //必须优先 release 掉 xid，才能正常 commit()
-                    TransactionContext.release();
                     TransactionalManager.commit(xid);
                 } else if (!rollbacked) {
-                    TransactionContext.release();
                     TransactionalManager.rollback(xid);
                 }
             }
             return success != null && success;
         } finally {
             //恢复上一级事务
-            if (prevXID != null) {
-                TransactionContext.hold(prevXID);
+            if (higherXID != null) {
+                TransactionContext.hold(higherXID);
             }
         }
     }
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionContext.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionContext.java
index 80692e14..5d1f6d5a 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionContext.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionContext.java
@@ -32,5 +32,4 @@ public class TransactionContext {
         XID_HOLDER.set(xid);
     }
 
-
 }
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionalManager.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionalManager.java
index 29857cf2..b123eab0 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionalManager.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionalManager.java
@@ -21,6 +21,7 @@ import org.apache.ibatis.logging.LogFactory;
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.util.Map;
+import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
@@ -34,6 +35,7 @@ public class TransactionalManager {
     private static final ThreadLocal<Map<String, Map<String, Connection>>> CONNECTION_HOLDER
             = ThreadLocal.withInitial(ConcurrentHashMap::new);
 
+
     public static void hold(String xid, String ds, Connection connection) {
         Map<String, Map<String, Connection>> holdMap = CONNECTION_HOLDER.get();
         Map<String, Connection> connMap = holdMap.get(xid);
@@ -63,6 +65,12 @@ public class TransactionalManager {
     }
 
 
+    public static String startTransactional() {
+        String xid = UUID.randomUUID().toString();
+        TransactionContext.hold(xid);
+        return xid;
+    }
+
     public static void commit(String xid) {
         release(xid, true);
     }
@@ -71,8 +79,10 @@ public class TransactionalManager {
         release(xid, false);
     }
 
-
     private static void release(String xid, boolean commit) {
+        //先release，才能正常的进行 commit 或者 rollback.
+        TransactionContext.release();
+
         Exception exception = null;
         Map<String, Map<String, Connection>> holdMap = CONNECTION_HOLDER.get();
         try {