Abstract: Building a large-aperture segmented space optical system is a comprehensive task involving disciplines such as optics, materials science, mechanics, and control theory. In order to achieve observation goals, high requirements have been placed on the motion accuracy of the opto-mechanical structure of space optical systems. Currently, how to effectively measure and correct the misalignment of mechanisms caused by complex environmental loads in space is an important problem that needs to be solved in order to achieve higher positional accuracy in situ. Relying on optical measurement systems to achieve high-precision in situ measurement of space mechanisms is the key to solve this problem. The key technologies and research status of precision optical measurement systems were reviewed from different measurement dimensions, different levels of accuracy, and different measurement principles, and their development trends and application scenarios in space optical systems were described and summarized.