[Objective] To meet the requirements of the IE5 international maximum energy efficiency class and address the issues of high cost in permanent magnet motors, excessive material consumption in asynchronous motors for achieving IE5 efficiency class, and low power factor in pure reluctance motors, this study developed a series of permanent magnet assisted synchronous reluctance motor (PMASRM) featuring high efficiency, high power factor, and low cost. [Methods] Firstly, the influences of key parameters, including the number of motor poles, air gap length, the number of flux barrier layers, flux barrier ratio, and rotor rib width, on electromagnetic performance such as torque, efficiency, and power factor were systematically investigated. Then, the finite element method was employed for parameter optimization design and torque-angle characteristic simulation, through which the optimal current control angle was determined. Moreover, an electromagnetic-structural coupled strength analysis was conducted on the rotor flux barrier bridge to guarantee mechanical reliability. Finally, the trial production and testing of nine prototypes across six specifications were completed. [Results] All prototypes achieved the IE5 energy efficiency class, and their power factors generally exceeded the requirements of industrial standards. Cost analysis results demonstrated that, at the same output power, the total cost of active materials for this series of motors was lower than that of IE4 efficiency class induction motors and permanent magnet motors, showing a particularly significant cost advantage. [Conclusion] The series of PMASRM developed in this study have successfully achieved the IE5 energy efficiency target. They demonstrate outstanding cost-performance ratio across most commonly used speed points, integrating both energy-saving and material-saving characteristics. With substantial market potential, the proposed motor series provides robust technical support for enhancing the international competitiveness of China’s motor industry.