安装brew：
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
替换成国内源：
cd "$(brew --repo)"
git remote set-url origin https://mirrors.ustc.edu.cn/brew.git
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://mirrors.ustc.edu.cn/homebrew-core.git
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-cask"
git remote set-url origin https://mirrors.ustc.edu.cn/homebrew-cask.git
echo 'export HOMEBREW_BOTTLE_DOMAIN=https://mirrors.ustc.edu.cn/homebrew-bottles' >> ~/.bash_profile
brew update
Let's go!
