Three-phase Vienna PFC circuit is widely used because of its high power factor and low harmonic current. In this paper, dual closed-loop PI control strategy is used to analyze and design the circuit control loop. For the problem that When the PI controller is saturated, the integral part cannot be desaturation in time, thus affecting the response speed of the circuit. The design of an integral modified PI controller is proposed. On the basis of the traditional double closed loop PI control strategy, the integral correction link is added to speed up the dynamic response of the system. The simulation model of the system is built in MATLAB, and the response speed of the improved circuit is analyzed and compared. The effectiveness of the Vienna rectifier system and the superiority of the proposed controller are verified by simulation.