Three-axis　vehicle　inertial　stabilization　platform　(VISP)　is　a　complex　MIMO　nonlinear　system.　Aiming　at　the　problem　of　uncertain　disturbance　in　servo　control　of　three-axis　VISP,　a　neural　network　backstepping　sliding　mode　controller　(NNBSMC)　is　designed.　Firstly,　backstepping　control　is　used　to　decouple　the　three-axis　VISP,　and　sliding　mode　control　law　is　introduced　to　increase　the　anti-interference　of　the　system.　Secondly,　the　RBF　neural　network　is　selected　as　the　disturbance　estimator　for　the　nonlinear　friction　between　the　frames　and　the　system　coupling　for　real-time　estimation　and　compensation.　Thirdly,　forward　stabilization　channel　is　used　to　deal　with　the　inaccuracy　of　modelling　parameters　to　ensure　the　stability　of　the　system.　Finally,　the　stability　of　closed　loop　system　is　analyzed　by　using　Lyapunov　theorem.　In　the　simulation　of　servo　control　and　attitude　locking,　NNBSMC　was　compared　with　the　dual-loop　PID　controller,　SMC　controller　and　BSMC　controller.　The　results　verify　the　effectiveness　and　robustness　of　the　proposed　control　algorithm.　©　2021,　Editorial　Department　of　Control　Theory　&　Applications　South　China　University　of　Technology.　All　right　reserved.