Induction furnace is an electric furnace that uses the induction electric heating effect of materials to heat or melt materials. The AC power supply used for the induction furnace includes power frequency (50 or 60 Hz), medium frequency (150 ~ 10000 Hz) and high frequency (higher than 10000 Hz). The main components of induction furnace include inductor, furnace body, power supply, capacitor and control system. Under the action of alternating electromagnetic field in the induction furnace, eddy current is generated in the material, so as to achieve the effect of heating or melting. Induction furnace is usually divided into induction heating furnace and smelting furnace. There are two types of smelting furnaces: coreless induction furnace and coreless induction furnace. Cored induction furnace is mainly used for melting and heat preservation of various cast iron and other metals. It can use waste furnace charge and has low melting cost. Coreless induction furnace is divided into power frequency induction furnace, triple frequency induction furnace, generator unit medium frequency induction furnace, thyristor medium frequency induction furnace and high frequency induction furnace.