The invention discloses a liquid crystal optical phased-array angular amplifier, which comprises cascade liquid crystal polarization gratings in a direction X, cascade liquid crystal polarization gratings in a direction Y, a liquid crystal wave plate drive and an emergent light beam polarization state converting wave plate. According to the liquid crystal optical phased-array angular amplifier, through setting the periods of the liquid crystal polarization gratings, the uniform discrete distribution of pointing angles is realized in a two-dimensional space; an interval between every two adjacent pointing angles is enabled to be the same with the self scanning range of a liquid crystal optical phased array; through designing the cascade structures of the liquid crystal polarization gratings, the influence of the circumstance of an oblique incident laser beam on efficiency dissipation is avoided, and the angular amplifier is enabled to have optimal diffraction efficiency; through optimizing on-load voltage on a liquid crystal wave plate of each stage, the precise control of the polarization state in the front of the liquid crystal polarization grating of each stage is realized; the diffraction efficiency of each stage is optimized.