查看一下user表，错误的起因就是在这里， root的plugin被修改成了auth_socket，用密码登陆的plugin应该是mysql_native_password

mysql> select user, plugin from mysql.user;
+-----------+-----------------------+
| user      | plugin                |
+-----------+-----------------------+
| root      | auth_socket           |
| mysql.sys | mysql_native_password |
| dev       | mysql_native_password |
+-----------+-----------------------+
3 rows in set (0.01 sec)



-- -------------------------------------------

mysql> update mysql.user set authentication_string=PASSWORD('password'), plugin='mysql_native_password' where user='root';
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

然后重启服务

 sudo service mysql restart

ok！