This paper presented a method of leading angle flux-weakening control for interior permanent magnet synchronous motor (IPMSM) on the electric vehicles, and achieved the purposes of high times, smooth and wide-speed operation and low cost of control systems. The control algorithm based on the utilization of inverter's DC bus voltage determines the deviation degree of the rotor synchronization rotation angle by constructing a new index loop of voltage and achieves the purpose of extending the operation speed range. The transition of flux-weakening is smooth, and the algorithm of leading angle flux-weakening control has nothing with parameters and realizes the high-time flux-weakening control of IPMSM. It not only meets the requirements of wide speed operation, but also reduces the cost of the whole system. The effectiveness of the proposed control scheme is verified by computer simulation and experimental results.