And what will happen to me then? They're cutting people's heads off all the time here.

“在这儿他们一直在砍头。”

The expression comes from when you kill people by cutting off their heads.

当你通过砍下他们的头来杀死人们时，就会出现这种表达方式。

She was outside cutting the dead heads off the roses.

【head】她在外面把枯萎的玫瑰花从花枝上剪掉。