1：linux登录mysql

[root@localhost mysql]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 19
Server version: 8.0.13 MySQL Community Server - GPL

Copyright (c) 2000, 2018, 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> 

2：查看user表,修改连接级别

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> select host,user from user;
+-----------+------------------+
| host      | user             |
+-----------+------------------+
| localhost | root             |
| localhost | mysql.infoschema |
| localhost | mysql.session    |
| localhost | mysql.sys        |
+-----------+------------------+
4 rows in set (0.00 sec)

可以看到,root用户的host值为localhost,这代表只能本地连接,将localhost修改为%

update user set host='%' where user='root';

3：可能你觉得到这一步就完事了,但是使用navicat连接测试时,会提示无法解析主机名相关的错误,这是mysql8的一些安全策略的问题,具体请左转google,解决办法如下

ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'yourpassword';
FLUSH PRIVILEGES;

4：完毕