[Objective] To address the issues in traditional flux-weakening control for electric vehicle two-phase motor drives—limited power in the flux-weakening region, decreased motor output torque as speed increases, and increased system volume and cost caused by a front-end Boost circuit—this paper proposes an integrated circuit scheme that combines a Boost converter and a two-phase half-bridge inverter based on three-phase bridge multiplexing. [Methods] To meet the wide-speed-range operation requirements of the motor drive system for electric vehicles, the working mechanisms of the Boost circuit and the two-phase half-bridge inverter circuit were analyzed, and a system topology based on three-phase bridge multiplexing was proposed and constructed. Based on this, the key parameter design and control algorithm design were carried out, and the proposed scheme was verified by combining modeling simulation with theoretical comparison. [Results] The results showed that the proposed scheme effectively improved the DC voltage utilization and achieved the integrated coordination of boost and drive functions with only a slight increase in system volume and cost. Without reducing the output torque, the motor speed regulation range was expanded by 36.08%, which verified the effectiveness of the scheme in wide-speed-range operation. [Conclusion] The proposed scheme effectively balances the requirements of wide-speed-range performance, system cost, and structural integration, providing a feasible technical path for the low-cost and highly integrated wide-speed-range implementation of electric vehicle motor drive systems, and possesses certain theoretical significance and engineering application value.