The invention relates to a wiring device for butt welding of ultra-high molecular weight polyethylene straight pipes and its working method, comprising a support base including a cross arm, a feeding device, a support roller and a control device; The second support vertical beam; the first support vertical beam is equipped with a shaping device, the shaping device includes a protective groove, a tooth surface pressing wheel, a first motor, a lead wire device, a wire feeding chute, a pressing wheel, and a heating component; the second The second support vertical beam is equipped with a cutting device including a disc pressing mechanism and a grinding mechanism. The disc pressing mechanism includes an upper slideway, a first slider, an upper pressing roller, an upper hydraulic cylinder, a second motor for the supporting roller, and a reduction box. The grinding mechanism includes a glide path, a first lower slider, a lower pressure roller, a lower hydraulic cylinder, a second lower slider, a grinding head, a third motor, and a stroke electric cylinder. The invention relates to a wiring device for butt welding of ultra-high molecular weight polyethylene straight pipes and a working method thereof, which automatically arranges regular electric heating wires to improve wiring efficiency, and the electric heating wires are reliably fixed on the outer wall of the straight pipe.