A device, an instrument and a belt for tying the cervix are provided. The device includes the belt and the instrument. The belt is used to tie the cervix. The instrument includes a first outer pipe, a second outer pipe and two fork structures. The first outer pipe and the second outer pipe are rotatable to each other. The two fork structures are connected individually to corresponding axial ends of the first outer pipe and the second outer pipe, respectively, and insert into the belt detachably.