* Wire sensing heating is a complex dynamic process of electricity, magnetic, heat, and phase change interaction. The design of the induction heating furnace should make the entire system efficiency and the lowest loss. By analysis of current skin effects in induction heating, it is pointed out that the ratio of heating wire diameter and penetration current depth is relatively suitable for the temperature of the magnetic material such as the steel wire in the heating process. Describeing the heating of the steel wire in the Curie temperature point, the higher frequency is used in the Curie temperature point, and the efficiency of the induction heating furnace can improve the efficiency of the induction heating furnace. For the optimum frequency of different diameter wires at different temperatures, design processing 4> 7. 1~~ 丨 2. 6mm steel rod induction heating line, the production line is compact inductor to reduce end magnetic fields to reduce end magnetic fields Leak, and strictly control the concentricity and air gap between the wire and the sensor. The continuous production of the oil back spring steel wire is achieved by intermediate frequency and super audio power supply induction, and it is very good to use in industrial production.