According to the generator excitation control system with uncertain parameters, a novel adaptive backstepping robust controller was designed. In the design process, based on the backstepping method for designing the controller, the nonlinear damping algorithm to reduce the "coefficient expansion" of the backstepping method was introduced, which could effectively improve the robustness of the controller. And the adaptive estimation of damping coefficient was designed by useing the I&I adaptive control method. The simulation research was carried out by MATLAB software to verify the effectiveness and superiority of the algorithm.