The invention discloses a fishtail bolt, comprising a fishtail rod, a first nut, a screw and a second nut, wherein the fishtail rod is fixedly connected with the upper end of the screw, the end part of the fishtail rod is provided with a through hole, after being connected with the upper end of the screw, the first nut is connected below the fishtail rod, the upper part of the screw is a bare rod, the lower part of the screw is provided with external threads, the second nut is provided with internal threads, and the second nut is movably connected with the screw through mutual matching of the external threads and the internal threads. In this way, the fishtail rod and the screw of the fishtail bolt are fixedly connected, and the second nut and the screw are movably connected, so that connection between steel rails is more convenient, the use is more convenient, the connection effect is better, and the fastening effect is better.