Abstract: Supercritical carbon dioxide (S-CO₂) cycle has advantages as high efficiency, compact structure, and short working fluid flow path, and can meet the requirements of rapid peak regulation and deep grid peak regulation in power grid. However, in practical applications, the performance and stability of the S-CO₂ cycle largely depend on the mechanical properties, corrosion resistance and oxidation resistance of superalloy materials. Firstly, the material selection of high-temperature heat exchanger for the S-CO₂ cycle was introduced. Secondly, the morphology characteristics of the oxide films of ferritic-martensitic alloys and austenitic stainless steels in the S-CO₂ environment were introduced, and the experimental research methods for oxide film failure were analyzed. Finally, the prediction model for the failure of oxide film was introduced. Results show that the material selection criteria for the S-H₂O cycle may also be applicable to the S-CO₂ cycle system under similar temperatures and pressures. Alloy heat exchangers in S-CO₂ environments will undergo oxidation-carbonization reactions. The carbonization phenomenon occurring at the oxide film/alloy interface will aggravate the failure of the oxide film.