Abstract: In this paper, to solve the problem of zero sequence current in the traditional open-winding drive system, a smooth spread control strategy based on phase-shift decoupling modulation was proposed for the less-rare-earth hybrid-excitation permanent magnet（HPM） motor. By deducing the relation between the phase-shift decoupling angle and the operating state of the open-winding motor drive system, an integral sliding mode controller was designed to achieve flexible adjustment of the open-winding drive system’s decoupling angle. Then, the smoother and wider speed expansion characteristics of the drive system can be achieved with smaller zero sequence component. In addition, the open-circuit fault of any inverter bridge arm for the open-winding motor drive system based on phase-shift decoupling control was investigated. The fault-tolerant operation under arbitrary phase-shift decoupling angles was capable to be realized with the winding reconnection. Also, the speed expansion range of the system will not be affected during the fault-tolerant operation. Finally, the prototype of the less-rare-earth HPM motor was processed and the proposed control strategy was verified by the theoretical analysis and experimental tests.