Optical synthetic aperture technology is an effective way to increase the effective aperture of telescopes, enhance their resolutions, and improve their light-gathering capabilities. However, the technical difficulty of large-aperture optical synthetic aperture systems grows exponentially with the increase in sub-aperture discreteness and the release of degrees of freedom. This paper compares the basic principles and structural forms of optical synthetic aperture systems, reviews the development history of large-aperture optical synthetic aperture systems represented by segmented, sparse aperture, and distributed configurations, and analyzes the technical challenges faced in key areas such as active optics, formation and control, and path planning. Furthermore, the development direction is proposed for the next generation of large-aperture optical synthetic aperture systems.