The threelevel inverter’s voltage output had one more step than twolevel inverter so that it had lower harmonics. Thus, the output waveform of threelevel inverter was better and was more suitable to realize sine wave. Moreover, each power device’s voltage stress of threelevel inverter was smaller than that of twolevel inverter. Then threelevel inverter was more fit for high voltage and large power volume converter development. Interior permanent magnet synchronous motor (IPMSM) was controlled with threephase sine wave input. Using threelevel inverter to drive IPMSM had such clear advantages as decreasing torque pulsation and easy to realize excellent speed modulation performance. The research of IPMSM vector control based on threelevel inverter was carried out. The simulation model of the whole system was built. Simulation results proved that the threelevel inverter voltage output was correct, IPMSM speed could follow the reference speed closely, and the dynamic and static responses were good.