Motor vehicle steering control system and steering control method capable of enabling the calculated result to have better reliability to provide more accurate assisting torque

This invention relates to a motor vehicle steering control system for executing a steering control method to perform steering of steerable wheels of a motor vehicle. The steering control method comprises: receiving a steering reference angle and an actual steering angle and calculating a control torque according to the steering reference angle and the actual steering angle; obtaining an actual steering angular speed and a steering reference angular speed according to a variation of the actual steering angle and the steering reference angle within a sampling time and obtaining a friction torque compensation according to the actual steering angular speed and the steering reference angular speed; estimating an aligning torque generated after the steering; and calculating an assisting torque according to the control torque, the friction torque compensation, and the aligning torque estimation, and outputting the assisting torque.