Device and method for splicing large steel bifurcated pipe in tunnel

The invention discloses a device for splicing a large steel bifurcated pipe in a tunnel. The device comprises a supporting gantry system, a fixed platform, a left sliding track, a right sliding track, a first movable trolley, a second movable trolley, a third movable trolley, a fourth movable trolley and an overhead hoist. A left draft gear is arranged in a left turnoff in the tunnel, a right draft gear is arranged in a right turnoff in the tunnel, and the supporting gantry system is fixedly connected with the tunnel bottom. The technical problems that an overhead anchor cannot be arranged, and no lifting equipment exists are effectively solved by the splicing device. The invention further discloses a method for splicing the large steel bifurcated pipe in the tunnel. The method includes the following steps of assembling a left process cone and bulkhead combined body; assembling a right process cone and bulkhead combined body; assembling a left bifurcated branch pipe section; assembling a right bifurcated branch pipe section; splicing the left bifurcated branch pipe section and the right bifurcated branch pipe section; splicing multiple bifurcated pipe fittings; splicing a big bulkhead. The splicing method is high in operation efficiency, capable of adapting to splicing a high-strength large-diameter large steel bifurcated pipe.