The rare earth permanent magnet synchronous motor (PMSM) has superior performance, but the high price of rare earth permanent magnet material leads to the increase of motor cost. A new type of permanent magnet synchronous motor with less rare earth is presented, and the permanent magnet is of the combined magnet poles Halbach structure. The structural characteristics of the less rare earth combined pole permanent magnet synchronous motor are analyzed, and on this basis, three kinds of combined magnet poles Halbach permanent magnet synchronous motor topology structures of T-type, HAT type and LREH type are proposed. Three less rare earth permanent magnet synchronous motors are analyzed in terms of no-load back electromotive force, no-load cogging torque and rated load electromagnetic torque and compared with rare-earth permanent magnet synchronous motors. The effect of the thickness of NdFeB and ferrite permanent magnets on the material cost of less rare earth permanent magnet synchronous motor with combined magnet poles is studied under equal torque conditions. The material costs of rare earth permanent magnet synchronous motor and three kinds of less rare earth permanent magnet synchronous motor is compared. Finite element simulation results show that LREH type less rare earth combined pole Halbach permanent magnet synchronous motor has better torque performance and lower material cost.