diff --git a/lib/mo-tester-1.0-SNAPSHOT.jar b/lib/mo-tester-1.0-SNAPSHOT.jar
index 033ffea31..0f3c8b48a 100644
Binary files a/lib/mo-tester-1.0-SNAPSHOT.jar and b/lib/mo-tester-1.0-SNAPSHOT.jar differ
diff --git a/src/main/java/io/mo/db/Executor.java b/src/main/java/io/mo/db/Executor.java
index af0306b26..b92674d6d 100755
--- a/src/main/java/io/mo/db/Executor.java
+++ b/src/main/java/io/mo/db/Executor.java
@@ -161,7 +161,9 @@ public static void run(TestScript script){
                         //reconnect to mo, and set db to last use db
                         LOG.warn(String.format("The mo-tester tries to re-connect to mo, con[id=%d, user=%s, pwd=%s, db=%s], please wait.....",
                                 command.getConn_id(),command.getConn_user(),command.getConn_pswd(),command.getUseDB()));
-                        getConnection(command).setCatalog(command.getUseDB());
+                        connection = getConnection(command);
+                        if(connection != null)
+                            connection.setCatalog(command.getUseDB());
                         continue;
                     }