1。安装brew（可百度brew官网，参考安装）

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

2.安装git

brew install git

3.备份旧的git

cd /usr/local/binmkdir backup-gitmv git* ./backup-git/

4.找到新的git安装目录

cd /usr/local/Cellar/git/2.20.1

5.回到根目录，配置环境变量

cd ~vim .bash_profile#输入export GIT=/usr/local/Cellar/git/2.20.1export PATH=$GIT/bin:$PATH:wq

6.刷新环境变量，使配置生效

source .bash_profile

参考资料:[1]: