The work aims to deposit FeCrAlY thin film on Zr alloy substrate and use it as a protection layer to alleviate the corrosion under high-temperature water vapor environment. The FeCrAlY thin film was deposited on Zr and glass substrate via magnetron sputtering method. The XRD and SEM were used to characterize the structure and morphology of FeCrAlY thin film. The XPS was employed to investigate the valence states change before and after corrosion under high-temperature water vapor environment. The corrosion property of Zr and FeCrAlY thin film coated on Zr was tested under high-temperature water vapor environment of 900 ℃. The results showed that FeCrAlY thin film coated on Zr displayed better anticorrosion property compared to Zr. The weight gain of FeCrAlY thin film coated on Zr was nearly 30% less than that of Zr. The FeCrAlY thin film deposited on Zr via magnetron sputtering method plays the role of protection layer under high-temperature water vapor environment. During the process of corrosion, Al2O3 passivation layer separates out with help of Cr because of “third element effect”. The separated Al2O3 layer plays as protection layer and inhibits corrosion.