The first of all, the multidisciplinary modeling and analyzing for the electric power steering system (EPS) is made. The design method based on the model is proposed and the EPS control system is analyzed. On the basis of deeply observing and studying S/T singular value curves, a robust control algorithm of back-calculation is put forward. After analyzing the deficiency in the single-loop control structure of the EPS, the dual-loop control structure of the EPS is developed. The inner loop controller is designed using the single neuron PID algorithm, and the new robust control algorithm is proposed to design the outer loop controller. The simulation results in the frequency-domain S/T curves of the EPS system and the hand force step input of the steering wheel show that the designed controller is simple and effective, and has good robust stability and robust performance.