The　eutectic　melting　reaction　of　Cr　coated　Zr　alloy　cladding　at　high　temperatures　can　cause　premature　failure　of　the　cladding　and　damage　the　integrity　of　the　fuel　element.　This　study　conducted　isothermal　oxidation　experiments　of　Cr　coated　Zr　alloy　cladding　under　steam　atmosphere　at　1400–1500　°C,　and　explored　its　high-temperature　oxidation　and　eutectic　melting　reaction　mechanism.　In　the　experiments,　the　unit　area　oxidation　weight　gain　of　the　cladding　follows　the　parabolic　law,　and　the　oxidation　weight　gain　rate　constant　contains　two　stages,　which　are　closely　related　to　the　failure　of　Cr　coating　and　the　formation　of　Cr　rich　phase.　The　outer　surface　of　the　cladding　undergoes　the　formation　of　a　＇regenerated　Cr　layer＇　and　its　re-oxidation　process,　and　the　color　changes　from　dark　purple　to　dark　green.　After　the　eutectic　melting　reaction　occurs,　the　thickness　of　the　Cr　coating　rapidly　decreases,　accelerating　the　establishment　of　O　diffusion　channels,　resulting　in　the　loss　of　the　Cr　coating＇s　antioxidant　effect,　and　this　process　is　positively　correlated　with　temperature.　The　eutectic　molten　phase　migrates　inward　during　the　oxidation　process　until　β-Zr　is　consumed.　The　eutectic　molten　phase　is　ultimately　completely　oxidized　to　Cr2O3　and　ZrO2.　This　study　provides　the　reference　for　understanding　the　oxidation　and　eutectic　melting　reaction　characteristics　of　Cr　coated　Zr　alloy　cladding　in　high-temperature　steam　atmosphere,　and　has　guiding　significance　for　improving　the　performance　of　nuclear　fuel　cladding　materials.　©　2025　Elsevier　B.V.