mysql -uroot -p
输入你的centos的密码
UPDATE mysql.user SET authentication_string = PASSWORD('MyNewPassword') WHERE User = 'root' AND Host = 'localhost';
注：如果显示 ERROR 1819 (HY000): Your password does not satisfy the current policy requirements，说明你的密码不符合安全要求，
FLUSH PRIVILEGES;
quit;

systemctl stop mysqld
systemctl set-environment MYSQLD_OPTS="--skip-grant-tables"
systemctl start mysqld
mysql -u root
UPDATE mysql.user SET authentication_string = PASSWORD('MyNewPassword') WHERE User = 'root' AND Host = 'localhost';
注：如果显示 ERROR 1819 (HY000): Your password does not satisfy the current policy requirements，说明你的密码不符合安全要求，
FLUSH PRIVILEGES;
quit;