Abstract: This paper builds and analyzes the mathematical model of three-phase PWM rectifier, and the model predictive control for PWM rectifier. By analysis and simulations for traditional single and double vector model predictive control, the reason why the total harmonic distortion (THD) performance of grid current in rectifier is researched. To improve THD performance of rectifier under model predictive control, this paper proposes modified single and double vector model predictive control methods, The methods improve the THD performance of grid current, and keep the best current and voltage dynamic performance. The simulation results verify the validity and effectiveness of proposed methods.