The arc spraying process uses two filamentous metal spray materials. The two wires are respectively connected to the positive and negative poles of the power supply (the power supply is a safe voltage lower than 36V), and the wire is automatically, evenly and continuously fed through the wire feeding device. In the conductive nozzle in an arc spray gun, when the ends of the two wires come into contact with each other, the resulting arc rapidly melts the end of the wire and atomizes the molten metal into fine particles by means of high-speed compressed air, The speed of jet to the surface of the workpiece.