Based on the working principle and process of quantum navigation and positioning system, its optical signal transmission system is designed. The characteristics and selection of key components in the system are analyzed. Under the given parameters and expected performance index, the implementation scheme of an optical signal transmission system is designed combined with the characteristics of the key components including optical antennas, two-dimensional turntables, coarse tracking detectors, fast mirrors, fine tracking detectors in the acquiring-tracking-pointing (ATP) system, and single photon detectors in the HOM interferometer. It lays a foundation for the establishment of the simulation platform of optical signal transmission system, implementation of hardware system and further improvement of positioning accuracy in quantum navigation and positioning system.