For large optical telescopes, the relative poses between the primary and secondary mirrors have very strict requirements. Due to the large quality of the primary mirror, the secondary mirror system is often designed as an adjustable mechanism with multiple degrees of freedom. It has an important impact on telescope imaging. As the diameter of the telescope continues to increase and the application scenarios continue to develop, the secondary mirror adjustment mechanism must not only ensure high precision, but also have a high load, and its design is becoming more and more challenging. In order to find a feasible solution for the adjustment mechanism of the secondary mirror of the large-aperture telescope, according to the development needs and different applications of the adjustment mechanism of the secondary mirror of the large-scale optical telescope, the different adjustment mechanisms of the secondary mirror are sorted, classified and compared. The advantages and disadvantages of the secondary mirror adjustment mechanism are summarized, and the future development of large-aperture telescopes is prospected.