Nb-based alloy possessed limited application service life at ultrahigh temperature (> 1400 degrees 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 degrees C in air was successfully achieved on Nb-based alloy thanked to multi-layered silicide coating. Through optimizing interfaces, the MoSi2/NbSi2 silicide coating with Al2O3-adsorbed-particles layer exhibited three-times higher of oxidation resistance capacity than the one without it. In MoSi2-Al2O3-NbSi2 multilayer coating, the Al2O3-adsorbed-particles layer playing as an element-diffusion barrier role, as well as the formed porous Nb5Si3 layer as a stress transition zone, contributed to the significant improvement. (C) 2018 Elsevier B.V. All rights reserved.