解决办法：
打开路径C:\Windows\System32\drivers\etc下的hosts文件，在文件末尾添加：
# GitHub Start
192.30.253.112 github.com
192.30.253.119 gist.github.com
151.101.184.133 assets-cdn.github.com
151.101.184.133 raw.githubusercontent.com
151.101.184.133 gist.githubusercontent.com
151.101.184.133 cloud.githubusercontent.com
151.101.184.133 camo.githubusercontent.com
151.101.184.133 avatars0.githubusercontent.com
151.101.184.133 avatars1.githubusercontent.com
151.101.184.133 avatars2.githubusercontent.com
151.101.184.133 avatars3.githubusercontent.com
151.101.184.133 avatars4.githubusercontent.com
151.101.184.133 avatars5.githubusercontent.com
151.101.184.133 avatars6.githubusercontent.com
151.101.184.133 avatars7.githubusercontent.com
151.101.184.133 avatars8.githubusercontent.com
# GitHub End
然后保存
如果在保存时出现禁止访问，权限不够，需要在右键单击hosts文件找到属性-安全-编辑，添加用户
然后在保存即可。
