Welding device for mechanical arm machining

The welding device comprises a base, a U-shaped plate is fixedly connected to the base, an electric push rod capable of moving longitudinally is arranged on the inner top of the U-shaped plate, a welding head is fixedly connected to the output end of the electric push rod, a guide groove is formed in the upper end of the base, and a clamping groove is formed in the lower end of the base. A ferromagnetic layer is arranged on the inner wall of the guide groove, two electromagnets are fixedly connected to the inner bottom of the guide groove, magnetic blocks abutting against the electromagnets are arranged at the upper ends of the electromagnets, and the magnetic poles of the faces, abutting against the electromagnets, of the magnetic blocks are opposite. The fixing block can be preliminarily positioned through the magnetic block and the ferromagnetic layer, the fixing block can be conveniently moved, then the welding positions of the two plate-shaped accessories can abut against each other conveniently, the mov