确定一下系统参数，系统参数不对

命令敲错了

set global validate_password_policy=0;

validate_password组件确认安装了吗？

#安装
mysql> INSTALL COMPONENT 'file://component_validate_password';
Query OK, 0 rows affected (0.01 sec)

#查看
mysql> SELECT * FROM mysql.component;
+--------------+--------------------+------------------------------------+
| component_id | component_group_id | component_urn                      |
+--------------+--------------------+------------------------------------+
|            2 |                  2 | file://component_validate_password |
+--------------+--------------------+------------------------------------+
1 row in set (0.00 sec)

#卸载
mysql> uninstall  COMPONENT 'file://component_validate_password';
Query OK, 0 rows affected (0.00 sec)