Solid-state photoconductive microwave source based on wide-bandgap photoconductive semiconductor is a new way of high power microwave generation. The scheme has the characteristics of high power density and wide frequency band, and its low time jitter characteristic makes it have great potential in power synthesis. The construction of active phased array of photoconductive microwave devices using optical beamforming network is an important way for the application of photoconductive microwave devices. In this paper, the principle of optical microwave phased array system is analyzed, and the theoretical models of differential true delay phased array and true delay phased array considering phase random error are constructed. The key factors affecting power synthesis and beam scanning are quantitatively analyzed and simulated, and the delay precision index is proposed.The results show that for the n×10 array transmitting signal at 1 GHz, when the delay phase variance is less than 10 ps, the pointing deviation is less than 0.2° and the peak gain loss is less than 2%. When the delay step accuracy is less than 10 ps, the pointing deviation is less than 0.2°, and the peak gain loss is less than 0.03%. On this basis, the real time delay network architecture of photoconductive microwave is designed, which provides a reference for the development of higher power and larger scale photoconductive microwave synthesis technology in the future.