Abstract: The high-temperature dome produces intense infrared radiation, which forms the background noise on the detector receiving surface and seriously affects the image quality. To assess the performance degradation as a result of aerodynamic heating of the conformal dome flying at high speed, this paper established the multi-physics coupling model of conformal domes under aerodynamic heating environment, the dome thermal radiation emission and transmission model. Based on these models, the temperature field, the stress field, the strain field and the deformation field of conformal domes were obtained, and the imaging quality of high-speed aircraft affected by heat radiation of conformal dome was analyzed. Results show that as time goes on, the maximum irradiance of the detector is increasing. At 10 s, the minimum value of the thermal interference irradiance of the conformal shroud at 0° attack angle is 0.094 W/m², and the maximum value is 0.108 W/m². Compared with conformal domes under the same working condition, the maximum irradiance of the spherical dome at 10 s is about 12 times and 7 times of the maximum irradiance of ellipsoid and parabolic dome, respectively. Conditions thermal radiation interference of the conformal dome has less effect on the detection system comparing with spherical dome, and does not have a fatal effect on the detection performance of the detector.