mysql -u root -p   #登陆数据库  
mysql> use mysql;  
mysql> update user set host = '%' where user = 'root';  #将用户root的host设为%  
mysql> flush privileges;  
mysql> select host,user from user;  #查看root的host是不是成功被修改成为%

修改用户密码,新密码可以和旧密码保持一致

ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'newpassword'; #更新一下用户的密码 root用户密码为newpassword