The invention belongs to a method and a device for welding antirust conductive metals on railway steel rail surfaces; wherein, the method includes the steps of rust moving, preheating, welding and slow cooling; the device comprises a vehicle body, a heating device, a swinging welding device and a slow cooling device. The invention can put an end to the misreport problem of a signal system owing to the rust grown on the rail surfaces to lead a signal interlocking system to obtain the reliable information; the device used in the method can effectively weld the antirust conductive metals on the railway steel rail surfaces and has the advantages of simple structure, fast construction speed and good application effect without affecting the inner quality of the steel rails.