1.查看可以被刪除的untracked files

git clean -f -n

2.刪除untracked files

git clean -f

If you want to also remove directories, run git clean -f -d or git clean -fd

If you just want to remove ignored files, rungit clean -f -X or git clean -fX

If you want to remove ignored as well as non-ignored files, run git clean -f -x or git clean -fx

Note the case difference on the X for the two latter commands.

原內容出自stackoverflow，備份以便以后查詢。