Abstract: To investigate the high-temperature mechanical properties of ceramic matrix composites (CMCs) in re-entry service environments, an aerothermal mechanical and oxygen coupling test platform was established in an arc wind tunnel. This platform utilizes an arc heater and a supersonic wind tunnel system to simulate a high-enthalpy, high-speed aerodynamic heating environment conducive to evaluating thermal protection materials. By adjusting the working gas mixture ratio of the heater, the oxidation and ablation atmosphere can be varied. Additionally, a material performance testing machine applies the necessary stress conditions to the thermal protection materials. On this aerodynamic thermal-oxygen coupling test platform, tests were conducted on CMCs at surface temperatures ranging from 1200°C to 1600°C, under pre-tensile forces of 600N to 1200N, and in various oxidation and ablation atmospheres. The ablation damage of the CMCs was assessed through uCT scanning and mass loss measurements, followed by uniaxial tensile tests on the tested specimens to evaluate their residual structural properties. The experiments investigated the mechanisms of ablation and oxidation damage mechanisms of CMCs.