service mysql stop

修改配置文件，添加一行代码

skip-grant-tables

然后重启mysql

service mysql start

接下来执行

mysql -p后面直接回车，就会进入mysql的命令行，然后依次执行如下命令

insert into mysql.user set user='root',ssl_cipher='',x509_issuer='',x509_subject='';

update mysql.user set Host='localhost',select_priv='y', insert_priv='y',update_priv='y', Alter_priv='y',delete_priv='y',create_priv='y',drop_priv='y',reload_priv='y',shutdown_priv='y',Process_priv='y',file_priv='y',grant_priv='y',References_priv='y',index_priv='y',create_user_priv='y',show_db_priv='y',super_priv='y',create_tmp_table_priv='y',Lock_tables_priv='y',execute_priv='y',repl_slave_priv='y',repl_client_priv='y',create_view_priv='y',show_view_priv='y',create_routine_priv='y',alter_routine_priv='y',create_user_priv='y' where user='root';

update mysql.user set password=password('123456') where user='root';

flush privileges;