Abstract: Deep space antenna array is one of the important measures to realize deep space exploration and communication with a very long distance. Based on the signal model of antenna array, the space power synthesis performance characeristics of the deep space antenna array are studied. The effects of time delay and phase compensation error of each antenna signal on the space power synthesis performance are analyzed, and the effects of formation of antenna array on the position and amplitude characteristics of grating lobes are studied. The simulation test results show that the grating lobes of the uniformly distributed square antenna array are evenly distributed and have a large amplitude. As the degree of non-uniform distribution of the antenna array increases, the grating lobes will become scattered and the amplitude will decrease, but the main lobe changes will not Not obvious. The grating lobes of the circular antenna array are scattered, while the main lobe and grating lobes of the L-shaped antenna array are both elliptical. It provides a certain reference for the design of deep space antenna array system.