This paper discusses a double three-phrase permanent magnet synchronous mathematic (DTP-PMSM) mode. Two kinds of analysis methods for DTP-PMSM Direct Torque Control theory research are provided. The first one is the flux linkage where the direct torque control (DTC) theory is similar to the three phrases PMSM. The second one is the flux linkage produced by each set of winding. The function relation of the torque and its angle can be obtained easily. Simulation shows that the torque characteristic has been researched on one or both set of windings. The simulation results have also shown that two approaches may be feasible and the motor operation may be selective in term of application occasion. The research result is a foundation of theory and application for the DTP-PMSM control system. ©2009 IEEE.