In order to improve the working performance of the gas deflector of aircraft carrier, the ablation test intended for simulating the takeoff condition is conducted by placing the test specimens of C/C-SiC composite in the wake flow of carrier-based aircraft so as to measure the ablative rate of the test specimens. The ablation mechanism and thermal shock damage of the test specimens are analyzed by adopting a scanning electron microscope (SEM) and micro-CT to observe the micro structure of the test specimens after ablated. By using energy dispersive spectrometry (EDS), the components of combustion products are measured to analyze the ablation mechanism and thermal shock damage of the test specimens. According to the result, the linear ablative rate of the test specimen is about 0.0405mm/s and its mass and its mass ablative rate is about 0.0349g/s. The heat affected zone experiences matrix crack and unapparent oxidation reaction. In the transition zone, the SiO2 produced by the reaction is precipitated around the carbon fibers and forms a sheathing structure, thus effectively retarding oxidation reaction from transferring inward and reducing the ablative rate of the test specimen. In the center of ablation, the retardation of SiC on oxidation reaction is small and the test specimen forms a concave pit, with carbon fibers being distributed in the shape of pointed bamboo shoots. On the whole, the material gives its outstanding anti-ablative performance.