The invention relates to a non-linear compensating controller in essence of a servo system, belonging to the field of industrial control. The compensating controller of the invention comprises a variable structure neural network feedback compensation part, forward adaptive compensation part and a robust compensation part; therefore, the controller can simultaneously compensate friction non-linearity and driver dead area non-linearity existing in the compensating system. The variable structure neural network compensates for the friction non-linearity in the system while the adaptive robust control carries out compensation control on the dead area non-linearity and external perturbation in a system driver; the variable structure neural network technology reduces network size and calculation amount and strengthens practicality of the controller; the adaptive robust control ensures static precision, transient performance and robustness of the system; applied to location tracking control of the electric motor, as indicated by actual operation results, the compensating controller of the invention can endow the system with excellent static tracking precision and robustness.