一、Windows下
解决方法：修改hosts文件

具体步骤参考:https://blog.csdn.net/qq_38232598/article/details/91346392

亲测有效！！！

二、Ubuntu下
按下ctrl＋alt＋T打开命令终端，输入：

nslookup github.com

按下ctrl＋alt＋T打开命令终端，再输入：

nslookup github.global.ssl.fastly.net

写入hosts文件，刷新缓存
按下ctrl＋alt＋T打开命令终端，输入：

sudo gedit /etc/hosts

然后在文件末尾加上：

# GitHub Start 
140.82.113.3      github.com
140.82.114.20     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
199.232.68.133     avatars0.githubusercontent.com
199.232.28.133     avatars1.githubusercontent.com
151.101.184.133    avatars1.githubusercontent.com
151.101.184.133    avatars2.githubusercontent.com
199.232.28.133     avatars2.githubusercontent.com
151.101.184.133    avatars3.githubusercontent.com
199.232.68.133     avatars3.githubusercontent.com
151.101.184.133    avatars4.githubusercontent.com
199.232.68.133     avatars4.githubusercontent.com
151.101.184.133    avatars5.githubusercontent.com
199.232.68.133     avatars5.githubusercontent.com
151.101.184.133    avatars6.githubusercontent.com
199.232.68.133     avatars6.githubusercontent.com
151.101.184.133    avatars7.githubusercontent.com
199.232.68.133     avatars7.githubusercontent.com
151.101.184.133    avatars8.githubusercontent.com
199.232.68.133     avatars8.githubusercontent.com

# GitHub End

最后刷新缓存：在命令终端输入：

sudo /etc/init.d/networking restart

亲测有效！！！