Abstract: Ultra-high temperature ceramics are one of the ideal potential materials for thermal protection in extremely high-temperature environments. Silicon carbide, owing to its exceptional mechanical and thermal performance, becomes a research hotspot in the area of ceramic matrix or oxidation-resistant coatings, significantly enhancing the oxidation and ablation resistance of thermal protection materials. However, the complex mechanisms of thermal response and evolution for the silicon carbide interface in the high-temperature boundary layer remain unclear, limiting its further modification in thermal protection system design. Reactive molecular dynamics (RMD) simulation method based on the reactive force field, provides new possibilities for investigating the complex interface evolution and thermal response mechanisms of silicon carbide at the atomic scale. In this study, the interfacial evolution of silicon carbide is investigated by employing the RMD simulation method, and the thermal response mechanism is explored under various temperature and pressure conditions, including the oxidation and sublimation phenomena, etc. Moreover, the oxidation rate, sublimation rate and material ablation rates are further calculated under typical operating conditions. Through comparing the calculated ablation recession rate with experimental results from literatures, a relative error within 10% is revealed, verifying the feasibility of applying RMD method in quantitative calculation of thermochemical reactions at the material interface.