The field distribution, overlap integral and the relationship between driving power and waveguide thickness variation of surface acoustic wave (SAW) acousto-optic modulator based on 165°Y-cut 75°Y-propagation LiNbO3 (165Y LN) has been simulated theoretically in this paper, and compared with the simulation results in other cut direction. This cut direction is located within the material decoupling surface and has the highest electromechanical coupling factor coefficient, making it a potential high performance cutting direction. The test results show that both TE and TM modes of 165Y-LN have lower driving power and larger overlap integral bandwidth at low frequency range, which makes 165°Y-75°Y LN suitable for fabrication high performance and polarization-insensitive SAW acoustic-optic devices.