Abstract: In order to raise the utilization ratio of permanent magnet synchronous motor bus voltage,and reduce the voltage vector angular deviation, a method with harmonic injection pulse width modulation was proposed based on voltage ratio zoom. In harmonic injection with look-up table type, it was taken as advancing the current respond rate to reduce the harmonic value computation time. A pulse width modulation method of voltage ratio zoom was utilized to eliminate the calculation deflection of voltage vector, and raise the utilization ratio of the bus voltage.The simulation and experimental results show that this kind of pulse width modulation can improve the utilization ratio of the bus voltage and motor response ability under high speed command.