1. 登录mysql
mysql -u root -p
//输入密码
2. 使用命令show global variables like 'port';查看端口号
mysql> show global variables like 'port';
3. 修改端口，编辑/etc/my.cnf文件，早期版本有可能是my.conf文件名，增加端口参数，并且设定端口，注意该端口未被使用，保存退出。
[root@test etc]# vi my.cnf
[mysqld]
port=3506
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
"my.cnf" 11L, 261C written
[root@test etc]#
4. 重启mysql
[root@test ~]# /etc/init.d/mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]