Abstract: When an aircraft re-enters the atmosphere, the high-speed air scour may introduce ultra-high heat flux and pressure on its surface. This double effect may cause serious thermal damage to the structural materials, and even lead to flight accidents. To solve this problem, a lightweight sandwich-structured thermal protection system with Al₂O₃/SiC aerogel as the thermal insulation layer was designed. Through the oxygen-acetylene ablation test, the thermal insulation performance of the thermal protection system under typical high temperature conditions was tested. The results show that the line ablation rate and mass ablation rate of the thermal protection system gradually decrease with the increase of the thickness of the thermal insulation layer. When the thickness of the layer was 14 mm, the line ablation rate and the mass ablation rate were 0.001 9 mm·s^-1 and 0.003 1 g·s^-1, respectively, and the erosion morphology has a good integrity. It indicates that the thermal protection system has appropriate thermal insulation and mechanical capabilities. Meanwhile, the thermo-mechanical coupling analysis of the thermal protection system was carried out by the finite element simulation method, and the ablation test results were verified.