Single-phase asynchronous motors have an irreplaceable role in small production fields such as household appliances and office equipment. However, due to the existence of small single-phase asynchronous motors with low power factor, low efficiency, vibration and noise, and other problems, the performance of a single-phase asynchronous motor, including efficiency, power factor, and vibration noise has been unable to meet the increasing needs of people. In this paper, a single-phase line-starting permanent magnet synchronous motor (SPLSPMSM) for air compressor is designed with the core size of Y series three-phase asynchronous motor for reference. The operating capacitance, the number of turns of the main stator winding, the turns ratio of the main and auxiliary windings, and the permanent magnet size are selected as optimization variables, and the efficiency, power factor, and starting torque are the optimization objectives. A regression model was developed by the response surface method (RSM) to optimize the performance of the motor, and the reliability of the response surface experiment was verified. The results show that the performance of the optimized motor is improved in terms of rated operation and starting performance.