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I. Core Background High-temperature corrosion of nuclear fuel is a critical issue for the safe operation of reactors. Following the Fukushima nuclear accident, there has been a significant increase in attention paid to its prevention and control within the industry, and related research continues to advance. II. Main corrosion mechanisms: High-temperature water/steam corrosion: Water under high temperature and pressure is highly corrosive; direct contact with uranium fuel leads to rapid erosion ； Traditional zirconium alloy cladding undergoes a zirconium-water reaction in high-temperature steam, producing large amounts of hydrogen and posing an explosion risk. Differential corrosion due to oxidation of alloy phases: For example, in Cr-doped UN fuel, the UN phase begins to oxidize at 400°C, while the U₂CrN₃ phase starts to oxidize at 430°C; as a result, the UN phase is corroded preferentially, which actually increases the overall corrosion rate, according to international academic research. Corrosion in a liquid metal environment: In lead-cooled fast reactors, element diffusion occurs in the ferritic/martensitic steel cladding within high-temperature liquid lead-bismuth, which damages the surface structure and leads to corrosion. III. Mainstream protection methods: New cladding materials – FeCrAl alloys benefit from a Cr-passivation layer formed on their surface, which greatly enhances their corrosion resistance, and they hold promise as alternatives to traditional zirconium alloys. Surface coating modification: The Cr-Nb alloy coating is suitable for pressurized water reactor conditions, providing effective protection for 45 minutes in high-temperature steam at 1100°C ； A Cr coating with a low grain boundary density can delay the oxidation of the zirconium alloy substrate to over 3000 seconds. Optimization of composition regulation: Adjusting the proportion of carbon in the FeNiCrAl alloy can increase the Cr content in the γ phase, reduce the thickness of the oxide film, and enhance resistance to high-temperature water corrosion.