Aiming at the high precision tracking problem of photoelectric tracking turntable,a backstepping sliding mode control system and algorithm are designed.Sliding mode control is introduced in the algorithm based on backstepping control,which improves the robustness of the controller.Through the simulation analysis,it can be seen that the performance of the algorithm is greatly improved compared with that of the backstepping control algorithm and the PID control algorithm.The step tracking response speed is increased by more than 21%,and the steady-state accuracy of the sinusoidal tracking and the steady-state accuracy under random disturbance are improved by two orders of magnitude,the pulse interference stabilization time isreduced by more than 0.7 s.The tracking accuracy of the photoelectric tracking turntable are well guaranteed.