Abstract: The paper gave a mathematical model of salient pole synchronous motor supplied power by three-lever inverter,introduced principle of three-level direct torque control of salient pole synchronous motor,described synthesis principle of synthesis virtual phase,and gave some simulation waveforms of three-level direct torque control of the salient pole synchronous motor based on synthesis virtual phase method.The simulation result showed that the method has some advantages such as low torque ripple and fast response,and so it has certain practical application value.