Abstract: A novel design of wide-band acousto-optic(AO) deflector is proposed. By rotating the coordinate system, the curved faces of refractive index of ordinary light and extraordinary light are not tangential in the new coordinate system. Based on this, curves of θ_i(f) and θ_d(f) under different rotating angel are systematically studied and the design parameters are also determined by solving the Dixon Equation. The results show that the central frequency of the AO deflector can be controlled by the rotating angel and the AO deflector can gain wider bandwidth simultaneously.