https://www.scootersoftware.com/support.php?zz=kb_vcs

Diff

At a Windows command prompt, enter the commands:
  git config --global diff.tool bc
  git config --global difftool.bc.path "c:/Program Files/Beyond Compare 4/bcomp.exe"


Note: For Git versions older than 2.2 (git --version) replace "bc" with "bc3" in the above instructions.

https://www.hack520.com/697.html

beyond compare 4 作为 git 的 diff 工具