Coherent detection has the advantages of fast response, high detection sensitivity, and good filtering performance, compared with direct detection. It is a key to improve the receiving sensitivity of optical wireless communication system. This paper summarizes the research progress in the field of coherent detection of optical wireless communication system, and introduces the research work of Xi'an University of Technology in the field of coherent detection technology, including the influences on the performance of wireless optical communication due to atmospheric turbulence suppression, angle of arrival fluctuations, amplitude fluctuations, channel noise, optical signal polarization, local oscillator optical power and light source linewidth, and the performance analysis of subcarrier modulated non-optical heterodyne detection system in ideal and non-ideal channels. Finally, the development direction of wireless optical coherent communication technology is prospected.称号。