其实就是 hosts 的问题，搜索了一圈，发现解决方案直接明了：

解决方法，打开路径 C:\Windows\System32\drivers\etc 下的 hosts 文件

# 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


这样修改 hosts 文件后，重新刷新 github 页面，就发现问题已经解决了。

上诉解答链接： https://blog.csdn.net/u013044310/article/details/103882463

亲测有效。