Aiming at the characteristics of non-linearity, uncertainty and susceptibility to disturbance of single-degree-of-freedom magnetic levitation ball system, a backstepping control method based on extended state observer is proposed to improve the control performance of the system. The method uses the extended state observer to estimate the position, velocity and disturbance information of the levitation ball in real time when the system is disturbed by uncertainty. In the method, the estimation is combined with the controller design, and then the backstepping method is used to design the levitation position tracking control law of the magnetic levitation ball, and the Lyapunov method is used to prove the final bounded convergence of the tracking error of the system. The simulation results show that when there is uncertainty in the system, the designed control law can realize the stable suspension of the ball, and can realize the position tracking according to the required suspension height position.