The invention discloses a rope body fastener. The rope body fastener comprises a tape threading body with at least one frame body and a clamping part, wherein the frame body comprises a connecting part and an elastic part; the frame body is divided into a penetrating-in hole and a penetrating-out hole by the clamping part; the clamping part comprises a supporting rod and an elastic piece; the supporting rod is placed between the connecting part and the elastic part of the frame body and is fixedly connected with the frame body; the elastic piece is moveably connected with the supporting rod and can move between the connecting part and the elastic part; the free end of the rope tape penetrates in from the penetrating-in hole, moves around the clamping part and penetrates out from the penetrating-out hole; when the free end of the rope tape is pulled and the elastic piece moves towards the elastic part, the penetrating-out hole is shrunk gradually and closes to the locking position gradually until the rope tape is clamped tightly; and when the elastic piece moves far away from the elastic part, the penetrating-hole is enlarged until the rope tape is loosened. The rope body fastener has a simple structure and low production cost and is widely applied to fastening and loosening rope bodies such as shoelaces and the like.