To address the fixed air-gap magnetic field of permanent magnet synchronous motors and the inefficiencies of traditional electrically excited motors, a novel parallel dual-rotor hybrid self-excited motor is introduced. Firstly, the proposed motor utilizing the harmonic excitation principle, it allows for flexible control of excitation current by adjusting harmonic voltage, which enhances speed control in medium and high-speed ranges. Secondly, under the premise of ensuring that the power remains unchanged, the proportion of each of the two parts is analyzed, and then the excitation source parameters are optimized and designed. Finally, the performance of the proposed motor is verified by adjusting the magnitude and direction of the excitation current and using the two-dimensional finite element model. The simulation results show that the proposed motor has a good ability to adjust the magnetism, and in the case of weak field, the amplitude of the back electromotive force is close to 0, which can effectively realize the speed adjustment.