This paper introduces the structure and working principles of the automotive electronic throttle control system. After analyzing the non-linear factor of the system, mathematical model of the system is built up. And the working principle of non-linear torque observer is described. Then incremental PID controller and non-linear torque compensator were designed and simulated in the matlab/simulink. From the result, we can see that the control precision of incremental PID controller is poor, and it also easily has an overshoot. However, PID controller based on non-linear torque observer has a better tracking performance. It can meet control requirements very well.