Through the MAC system prompt direct installation of git, after installation found that the local sshkey and GitHub account link, has been prompted "Connection closed by 192.30.253.112 port 22", check the log found no problem. So it is suspected that the GIT installation was wrong. Under terminal, you can see the git's address at "/ usr/bin/git" and enter "sudo rm-rf/usr/bin/git", but it is unsuccessful.
For uninstalling git, please reply as soon as possible. Thank you!