The molybdenum spot welding is composed of two pieces of metal with good conductive function. The center of the two pieces of metal is insulated. As long as there is a contact at the top, this contact constitutes a small resistance at the bottom of the welding head. Is flat and lubricated. When operating the machine, when the molybdenum spot welding head is pressed on the enameled wire by pneumatic means or with a foot pedal, the pressure will continue to increase. When the reaction fore of the enameled wire on the welding head reaches the set welding pressure, Will trigger a pulse current, the current time is very short, usually between of few milliseconds to ten milliseconds, and the magnitude is about tens to more than one hundred amperes. The current flows through the bottom of the welding head, and there is a contact resistance at the top of the welding head. When the resistance is contacted, it will generate heat and sparks. This heat can remove the varnish of the enameled wire and a lot of heat will be transferred to the copper wire inside the enameled wire superior, part of the current will flow from the bottom of the welding head through the burnt-out copper wire. The copper wire itself is also heating. The temperature of the copper wire will reach the melting point before the melting point in a short time. Under the effect of pressure, it will form a new metal with the underlying metal. The nugget, in this way, the enameled wire is connected to the metal substrate.