Tip-tilt mirror is a type of precision optical equipment that controls the direction of beam propagation in modern photoelectric systems. It has been utilized in space laser communications, adaptive optics, vehicle/airborne laser systems, image stabilization, astronomical telescopes, confocal microscopy, real-time laser scanning, capture target tracking, and other applications. The tip-tilt mirror is used in adaptive optics to correct the phase wavefront caused by atmospheric turbulence, which accounts for approximately 87% of the overall tilt. As a result, the tip-tilt mirror helps to rectify the first-order tilt of the system.The closed-loop performance of the adaptive optics system is severely harmed because the tip-tilt mirror is susceptible to wind vibration, equipment vibration, and platform vibration. As a result, the vibration must be minimized to approach the diffraction limit of optics. The standard closed-loop feedback control is ineffective in suppressing the vibration of the tip-tilt mirror, reducing closed-loop performance. In consequence, research into novel anti-vibration technology is critical to improving the closed-loop performance of the tip-tilt mirror. There are numerous methods for reducing vibration in use today. For example, literature offered a disturbance-based feedforward control method to suppress structural vibration of the tip-tilt mirror system, which involved measuring the disturbance with an accelerometer or a gyroscope and then feeding the disturbance with signal reconstruction. Returning to the system, the controller is not limited by low-rate sampling because it can produce a large suppression bandwidth. Additional measurement equipment, on the other hand, will raise the cost of the system as well as its complexity and analytical difficulty. Accelerometers or gyroscopes suffer from severe low-frequency drift and high-frequency noise. Existing control systems face extra control issues as a result of the accuracy of vibration estimation. Many enhanced control structures and optimized controllers, such as the Linear Quadratic Gaussian controller (LQG) and H∞/H2controller, have been developed based on the assumption of perturbation feedforward control. The results demonstrate that these strategies can improve the closed-loop performance of the system by 20% to 30%. However, the performance of the closed-loop system is dependent on the model accuracy and vibration of the controlled object. For example, in the tip-tilt mirror control system, if the model error is considerable, the performance of the system would be severely hampered. Because interference normally occurs in the low-frequency domain while sensor noise occurs in the high-frequency domain, a disturbance observer is employed to suppress interference in the low-frequency domain when the interference can be reliably estimated or measured. The Q-filter is commonly employed as an optimum filter in various servo control systems^{to maximize closed-loop performance in terms of control bandwidth and robust stability. When low-frequency and intermediate-frequency interference are significant, the high bandwidth of the low-pass filter is necessary. Sliding Mode Control (SMC) is widely used in industry because of its simple algorithm, strong anti-interference ability, and ability to overcome system uncertainty. However, the uncertainty existing in many practical systems does not satisfy the matching conditions of the system. For example permanent magnet synchronous motor system due to uncertainty caused by parameter variation and load torque, flight control system without dynamic modeling, external wind vibration, and parameter variation causing concentrated disturbance torque, For these systems, the sliding-mode motion of conventional SMC suffers from mismatch perturbations, which greatly reduces their robustness.To solve the control problem of the tip-tilt mirror in Adaptive Optics with the external disturbance, a disturbance observer was designed based on the sliding mode control (DOB-SMC) to suppress structural vibration. A new disturbance observer (DOB) was added to the traditional SMC method in the tip-tilt mirror control system, and a new sliding mode control rate was designed to suppress chattering. The improved DOB was not limited by precise models. And the emulation proved that this method is achievable. The experimental results showed that the control error of the azimuth axis is reduced from 1.637 μrad to 1.083 μrad, and the accuracy is improved by about 51.2%. The control error of the pitch axis is reduced from 1.966 μrad to 1.614 μrad, and the accuracy is improved by about 21.8%. This method can greatly weaken the inherent chattering and external disturbance of the system, and improve the stability of the tip-tilt mirror system.}