In view of the shortcomings of common hysteresis current control, the hysteresis loops are fixed and the switching frequency changes are inadequate. A strategy of adaptive hysteresis loop current control with variable switching frequency is proposed. The mathematical model of the main circuit topology of VSR system controlled by three-phase PWM and the hysteresis width control principle equation are derived in detail. The relationship between switching frequency and hysteresis width is obtained. Finally,by modeling and simulation in Matlab/Simulink environment, the simulation results show that the rectifier network measurement current is sinusoidal, and the DC side output voltage response is fast, the overshoot is small and the waveform is stable, the harmonic content and the total harmonic distortion of the input phase voltage and the phase current are all smaller than those of the national standard.