The PI parameter setting of double closed-loop vector control of voltage source PWM rectifier is very important and largely depending on experience with few references available. In this paper, the influence of the PI parameters on the output dc voltage waveform of the rectifier is studied by simulation in Matlab/Simulink, based on which a simple and step-by-step method for the PI parameter setting is proposed. Some examples are given to illustrate the application and effectiveness of this method.