A　novel　optimum　design　method　of　LiNbO3　anisotropic　acousto-optic　device　based　on　beam　steering　is　put　forward,　the　accurate　design　parameters　under　different　incident　light　angle　and　different　number　of　transducers　are　systematically　calculated.　The　results　show　that　anisotropic　acousto-optic　device　designed　by　this　new　method　can　realize　beam　steering　and　can　gain　wider　3　dB　bandwidth　and　higher　diffractive　efficiency　simultaneously.