This paper proposes a composite feedforward-feedback controller for a generator excitation system. By integrating both feedforward and feedback compensation, the composite controller composes a feedforward approximate controller and an error-feedback proportional-integral-derivative (PID) compensator. The feedforward controller is derived based on an approximation model method, which not only avoids complex computation, but also avoids online learning or adjustment. Only a general support vector machine (SVM) modeling technique is involved in a feedforward controller implement. Meanwhile, the feedback controller is constructed using a PID controller. Then the attenuation of both disturbances and estimated errors is guaranteed. Several simulations illustrate the effectiveness of the composite excitation controller.