It adopts the most advanced MOS, IGBT frequency conversion control technologies to realize automatic tracking of frequency. It has the constant current and power control function, which can significantly optimize metal heating process, realize the high efficiency and fast heating and bring into play the superior performance of the products. About ten types fault protection and display of over-current, over-voltage, water shortage and phase missing can provide higher reliability and durability. It is safe and reliable, and requires no equipments of ten thousand voltage, and thus can ensure the safe operation. It is available for infrared temperature measurement, which can realize the automatic control of temperature, improve the heating performance and simplify the manual operation.