Abstract: The infrared heating facilities are universally used in the spacecraft thermal vacuum tests. To improve the accuracy and the efficiency of the CAD based design process in the numerical simulation for complicated configurations, this paper, for an umbrella-shaped antenna, with an infrared heating cage as the heating apparatus, carries out the numerical analysis of the heating process with a simplified model, as well as an effective heating panel method, in which the computation resource requirement is reduced to an affordable level for engineering applications. It is confirmed by comparing with the experimental data that the numerical simulation is effective in providing guidances for the design of heating facilities used for the thermal vacuum test of aerospace products.