Aerodynamic heating effect simulation device on the ground is the core part of ground testing equipment for aero-load imaging performance. We design an optical window for aerodynamic heating effects simulation device on the ground. Using the combination of theoretical calculation and simulation model, we elaborate optical window design theory in the aerodynamic environment. First, we use the theory of Computational Fluid Dynamics (CFD) to do a simulation, and achieve the toughest condition value by computing pressure and temperature values. Then according to the classical strength theory and fracture mechanics, we propose the requirements of optical materials processing, and design the thickness of the window meeting the security requirements. At last, we verify that it is a rational design by means of the coupled simulation of fluid-solid thermal, and optimize the thickness of the window according to optical imaging quality.