In order to optimize the modulation strategy of three-level full power converter, and based on the diode neutral pint clamped NPC, an analysis has been made of the NPC space vector PWM (SVPWM) algorithm. On the basis of the algorithm, the two-dimensional αβ space vector plane is to be converted to the three-dimensional cubic vector, followed by an analysis of the three-dimensional space vector PWM 3D-SVPWM algorithm of NPC and a simulation of the rectifier of NPC converter by using PSIM simulation software. The simulation results verify the effectiveness of 3D-SVPWM modulation strategy for the diode neutral point clamped converter.