The invention disclose a power supply circuit. The power supply circuit includes one or a plurality of first-stage voltage conversion circuits and one or a plurality of second-stage voltage conversion circuits; an input end of the first-stage voltage conversion circuit is coupled to a power supply; the first-stage voltage conversion circuit is configured to convert a first voltage received at the input end into a second voltage, where the second voltage is less than the first voltage; an input end of the second-stage voltage conversion circuit is coupled to an output end of the first-stage voltage conversion circuit; the second-stage voltage conversion circuit is configured to convert the second voltage into a third voltage, and supply the third voltage to a load.