The technology of optical phased array is a new beam deflection technology with the advantages of fast scanning, anti-jamming, high resolution and secrecy. But grating lobe is one of the bottleneck problems in the research optical phased array technology. Incorporating with the history, principles, development actuality and tendency of optical phased array technology, the influences of grating lobe are explained. Based on the presented methods of grating lobes reducing, a new method of changing the incident light phases of irregular optical phased array is introduced. The grating lobes of optical phased array are restrained effectively by the method. The advantages and disadvantages of three methods are discussed. And the development prospects of optical phased array technology are forecasted.