参考博客：MySQL8.0登录提示caching_sha2_password问题解决方法

修改方式

一.修改my.cnf配置文件

[mysqld]
default_authentication_plugin = mysql_native_password

二.修改身份验证类型(修改密码)

ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
flush privileges;

验证结果

SELECT Host, User, plugin from user;
+-----------+------------------+-----------------------+
| Host      | User             | plugin                |
+-----------+------------------+-----------------------+
| %         | root             | mysql_native_password |
| localhost | mysql.infoschema | caching_sha2_password |
| localhost | mysql.session    | caching_sha2_password |
| localhost | mysql.sys        | caching_sha2_password |
| localhost | root             | mysql_native_password |
+-----------+------------------+-----------------------+
5 rows in set (0.00 sec)