1、使用lsb_release -a命令查看

[root@sky9896sky]# lsb_release -a
bash:lsb_release: command not found
[root@sky9896sky]#yum install lsb –y
[root@sky9896sky]# lsb_release -a
LSBVersion:base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
DistributorID: CentOS
Description:    CentOS release 6.7 (Final)
Release:        6.7
Codename:       Final

2、使用cat /etc/redhat-release命令查看

[root@sky9896 sky]# cat /etc/redhat-release
CentOSrelease 6.7 (Final)

推荐教程：centos教程