一共分為兩部：

1.在命令列下：

   生成金鑰：   ssh-keygen -t rsa -C "tx"                              tx    可以換成你想要的其他的名字

  有需要輸入的直接enter跳過就可以，不用設定密碼，要不以後每次clone都要輸入密碼，麻煩

[email protected]:~$ ssh-keygen -t rsa -C "tx"
Generating public/private rsa key pair.
Enter file in which to save the key (/home/shl/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/shl/.ssh/id_rsa.
Your public key has been saved in /home/shl/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:09NO3UEYr9zwM+lS+hIl83uCuE1QVonNBHEZa06GblA tx
The key's randomart image is:
+---[RSA 2048]----+
|            EOB= |
|           ..=B. |
|          . +.=o |
|         . *.O=oo|
|        S + =oBB.|
|         . * .+.o|
|           .o+...|
|          .o..+..|
|          ... .o.|
+----[SHA256]-----+
 

2.    命令列下輸入：   cat  /home/shl/.ssh/id_rsa.pub

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC3hNw/xETxEyRppLZ+MW+imNhJW3ySjESZdylGZZRx0J6zUWjucSD8qFJhUbQhwA6E182qes+AYuR+Yg3hT3cOYTPe14rr9JECGzAnQ9BEBq0HrzICqx1Liq+cOC4N6KNawh9r2/vytoNoaAZ46cn0em9m9SgoTW9Ld2h2Zv0NR0svvm9IAXxhJ9C4WezebP5jn9rCOn1VwaF36639hBjI5h7Sc9Kh6PzwblWXKU8rmJKs8H794xE5FVmrzVIWKpLtbx3smZYKFOLm9NZV9ORV18iYeM2UKmezRl4m26Lu/mJ5eEmbElx44NeyBPUOPb9vPX70y1Q1IptYrmDcZQ8l tx

把生成的輸入到github的  setting->SSH and GPG keys  下的key中即可