use mysql
update user set password=password("new_password") where user="user_name";
flush privileges;
或者
alter user 'user_name'@'localhost' identified by 'new_password';
flush privileges;
或者
update mysql.user set authentication_string=password('new_password') where user='user_name' ;
flush privileges;
5.6以及以前
update mysql.user set password=password('newpass') where user='用户名';
flush privileges;
5.7版本
update mysql.user set password=authentication_string('newpass') where user='用户名';
flush privileges;