The topology of three-phase voltage-source PWM rectifier(VSR) and the basic principle of voltage oriented control(VOC) were presented.Given the shortage of the traditional space vector pulse width modulation(SVPWM) algorithm applied in three-phase VSR, this paper puts forward an optimized SVPWM, by which the sector can be judged according to the rotating argument of voltage space vector, and the function time of basic voltage vector can be calculated based on the 3 phase voltage difference computation.Compared with the former two methods, the coordinate transformation and trigonometric calculation are completely omitted and the algorithm steps are simplified in the optimized SVPWM.The validity and practicability can be verified through the simulation of VOC system with MATLAB/SIMULINK.