[Objective] Dual-rotor axial-flux permanent magnet synchronous motor (AFPMSM) attracts significant attention in applications such as automotive in-wheel drives and wind power generation due to their high torque density and compact structure. However, traditional surface-mounted permanent magnet motors exhibit low inductance and poor field-weakening capability. To address this issue, this paper proposes a comprehensive optimization design for an 8-pole 48-slot yokeless stator AFPMSM. [Methods] The constant power speed range of a yokeless stator AFPMSM was broadened while maintaining high torque density, through the design of a d-axis magnetic bridge. The key structural parameters influencing the field-weakening performance were thoroughly analyzed to identify the optimization variables. To significantly enhance the optimization efficiency, the three-dimensional finite element model was converted into a two-dimensional equivalent model for multi-objective optimization, and the accuracy of the equivalent conversion was validated. [Results] The simulation results indicated that the yokeless stator AFPMSM achieved an output torque of 96.2 N·m and a constant power speed range of 5∶1. [Conclusion] The proposed motor design effectively expands the constant power speed range while meeting the requirement for high torque density. system efficiency and operational stability.