M. F. Thyristor (controllable silicon) power supply transfer a work frequency 50Hz AC power supply to DC power supply by 3-phase bridge rectifying circuit and provide single phase M. F. To load by parallel inverter after go through filter (DC reactor). The equipment adopts 89C51 single chip as core control with massive integrate circuit, based on exerting powerful computer software and hardware function it achieves the best regulation on rectifying and inverting.