1.首先删除redhat原有的yum ，因为redhat 原本的yum 没有注册为redhat用户是用不了的，输入如下命令行：
rpm -e yum --nodeps
2.下载163的yum 安装
wget http://mirrors.163.com/centos/7.3.1611/os/x86_64/Packages/yum-3.4.3-150.el7.centos.noarch.rpm
3.安装下载的rpm包
rpm -ivh *.rpm
4.编辑文件/etc/yum.repos.d/rhel-debuginfo.repo并写入，删除自带的.repo文件
[base]
name=CentOS-$releasever - Base
baseurl=http://mirrors.163.com/centos/7.3.1611/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.163.com/centos/7.3.1611/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.163.com/centos/7.3.1611/extras//$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.163.com/centos/7.3.1611/centosplus//$basearch/
gpgcheck=1
enabled=0
5.清除yum缓存，执行
yum clean all
现在可以安装软件进行测试了
