A FW strategy is proposed for the motor control of the electric power steering (EPS) system of electric vehicles, specifically targeting the working condition of emergency obstacle avoidance. The strategy, called leading angle flux-weakening (FW) control, utilizes the Particle Swarm Optimization (PSO) algorithm and uses the voltage utilization rate as the control variable. It transforms the oversaturation amount of the feedforward operation into the FW leading angle, thereby achieving FW speed expansion. This strategy addresses the issues of poor follower performance and poor interchangeability. To address the challenge of determining multiple controller parameters, the PSO method is employed to optimize the parameters offline. Additionally, the integral anti-windup control rate is applied to mitigate the integral saturation issue of the leading angle controller, preventing the motor in the FW control stage from saturation. The optimized FW control strategy, including the leading angle, is evaluated through simulations under two different working conditions: fixed load and rapid acceleration. The simulation results verify the viability and efficacy of the proposed control scheme.