The aerodynamic optical effect is calculated and analyzed for the shape of THAAD-like infrared seeker, and it is used in aircraft design. Considering the thermochemical non-equilibrium effect and the coupling effect of material heat transfer, high-speed flow calculation software NNW-HyFLOW is used to simulate the flow field in typical state of the seeker. The flow field parameters such as density, temperature and pressure and the temperature field parameters of the window are obtained. Based on the flow field parameters, the infrared optical transmission imaging calculation is carried out by using the aero-optical transmission effect calculation function in HyFLOW. The thermal radiation calculation of flow field and optical window is carried out by using the aerooptical radiation effect calculation module. The calculation results show that when the THAAD-like seeker flies above 30 km, the flow field and optical window will not affect the optical transmission imaging of the target signal, but the thermal radiation effect of the flow field and window will affect the target recognition of the seeker. However, when the infrared seeker flies at a high altitude, the influence diminishes.