1.修改/etc/my.conf，添加参数skip-grant-tables
2.重启mysql
service mysqld stop
service mysqld start
3.用root 直接登录
[root@bogon ~]# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.11 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
4.修改密码
mysql> alter user 'root'@'localhost' identified by 'newpassword';
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement
mysql>
这种方式不好使，换一种方式：
mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> update user set authentication_string=PASSWORD('newpassword') where User='root';
Query OK, 1 row affected, 1 warning (0.07 sec)
Rows matched: 1 Changed: 1 Warnings: 1
mysql>
5.将/ect/my.conf 修改回来，重启mysql 测试新密码
[root@bogon ~]# service mysqld stop
Stopping mysqld: [ OK ]
[root@bogon ~]# service mysqld start
Starting mysqld: [ OK ]
[root@bogon ~]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.11 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
修改完成
