As a DC voltage-regulating control power supply, the DC switching power supply for solar silicon single-crystal furnace adopts DSP and CPLD as the control core, IGBT as the power inverting device and high-frequency ultracrystalline transformer as the load-matching transformer. Adopting fast diode full-wave rectification, it realizes continuously adjustable output power by the phase controlled regulation way. In the entire inverting work process, by adopting high-precision power closed-loop control and LCC quasi-resonant mode, it realizes IGBT soft switching and reduces the switching losses of IGBT as well as the electromagnetic emission and conducted interference generated by the power supply to the outside world, what’s more, its multiple given signal selection functions and isolated conversion & output of output DC voltage, current and power facilitate the remote monitoring of PLC and host computer. For the power supply, the conversion efficiency is higher than 0.92, the power facto