Optical phased array technology has the advantages of fast scanning speed, high scanning precision and high sensitivity, but the existence of grating lobes largely limits its characteristics.An optimized unequal spacing method is proposed for beam scanning control of optical phased arrays.The effects of optical phased arrays with unequal element spacing on grating lobe suppression are analyzed.The minimum Peak Side-Lobe Level (PSLL) is obtained by optimizing the spacing of adjacent elements by an improved particle swarm optimization algorithm.The data simulation of the one-dimensional optical phased array shows that, optimizing the element distribution with the improved particle swarm optimization algorithm can suppress the grating lobes well,and the PSLL can be as low as 0.2 or less.