An effective method combining the active damping control with an improved SVPWM technology is proposed to reduce grid-side current distortion and system oscillation caused by current source PWM rectifier LC filter resonance. The virtual harmonic active damper control strategy, which adds an equivalent damping resistor, can suppress the current distortion and oscillation caused by LC resonance without affecting the fundamental power flow. Mathematical model of BUCK-type PWM rectifier is analyzed, advantages and disadvantages of the passive damping and active damping control are compared, and active damping compensator is introduced in the improved SVPWM rectifier. The performance of the proposed method is verified by simulation and experimental results. The distortion of the line current is effectively reduced and the stability of the system is improved. It has a certain engineering value.