This paper presents a two-stage AC-DC circuit design scheme. After analysing the current AC-DC application status and circuit scheme, as well as the main control strategy, making a choice that use totem-pole PFC as the front-end converter with modulation mode CCM, and the control method is voltage feed-forward control based on the average current, which converts the grid voltage (85–265 Vrms) to 400 V DC output voltage and has the anti-interference capability. A two-switch forward converter scheme is used in the back-end converter, and a peak current control strategy based on slope compensation is designed. The circuit is able to stabilise the output voltage of 80 V, the rated power is 800 W, the power factor is more than 0.99, and it is able to respond quickly to the fluctuation of the input AC power and the output load. The current distortion rate is about 5.31% and the overall efficiency of the circuit is about 96.7%. The simulation is verified by Matlab/simulink and the experimental results are analysed and discussed.