Abstract: This study simulated the aero-optical effect around the turret at different Mach numbers for three turret designs, calculated the density distribution of the flow field and the optical path difference after transmission in the flow field. The optical path difference increases with the increase of Mach number. The optical distortion over the turret field-of-regard is dependent on the beam direction, and there is large optical distortion in wake area. When the speed reaches transonic, the top of the turret will also produce large optical distortion. For different turret designs, the smaller the curvature, the smaller the aero-optical effect.