Nb-based alloy possessed limited application service life at ultrahigh temperature (>1400 °C) in air even taking the effective protective coating strategy into consideration for last decades. In this work a long duration of above 128 h at 1500 °C in air was successfully achieved on Nb-based alloy thanked to multi-layered silicide coating. Through optimizing interfaces, the MoSi 2 /NbSi 2 silicide coating with Al 2 O 3 -adsorbed-particles layer exhibited three-times higher of oxidation resistance capacity than the one without it. In MoSi 2 -Al 2 O 3 -NbSi 2 multilayer coating, the Al 2 O 3 -adsorbed-particles layer playing as an element-diffusion barrier role, as well as the formed porous Nb 5 Si 3 layer as a stress transition zone, contributed to the significant improvement. [ABSTRACT FROM AUTHOR]