Abstract: The flow field before a hypersonic vehicle flying in the atmosphere consists of high temperature and high pressure gas. The temperature of the vehicle's optical dome rises rapidly due to aerodynamic heating. IR radiation of the high temperature gas and dome bring severe aero-thermo-radiation effects which decreases the SNR of the detection system. According to radiation characteristies of non-gray gas mixtures and dome materials, simulation of the aero-thermo-radiation of a blunt cone body vehicle with sphere dome ahead was proposed based on infrared radiation transfer model. And then, the development of aero-thermo-radiation with time and different dome material were studied. The experimental results show that the high temperature gas radiant intensity is closely interrelated with the vehicle' movement, and the dome radiation increases rapidly with time, which becomes major factor of the aero-thermo-radiation gradually. Thus, restraining the velocity and range of the dome's temperature rising is the key to weaken aero-thermo-radiation effects.