An ABFC (adaptive backstepping fuzzy control) strategy is presented for one elevation equilibrator electro-hydraulic servo system of vehicle-mounted artillery with nonmatching uncertainty and parameters time-varying. Method of backstepping is used to overcome the problem of nonmatching uncertainty, adaption laws are adopted to eliminate the unknown parameters online. Fuzzy control is adopted to reduce the switching chattering phenomenon. Co-simulation results show that the ABFC strategy tracks the desired tracking trajectory well. The designed controller has nicer robustness and lower steady-state errors.