First principles based on density functional theory, the establishment of Al2O3 and RuO2 crystal cell model. the alloy oxide of Al2O3 and RuO2 that the internal oxidation of RuAl, The results show:the oxidation energy of Al2O3 to -11.43eV,the oxidation energy of RuO2 to -2.28eV, Al2O3 is more stable than the structural stability of RuO2.Through the analysis of density of States, charge density of Bander,W alloy to enhance the antioxidant properties of RuAl is the fundamental reason: due to the adsorption effect of W on the O, the W around the Al-O and Ru-O bond strength decrease,the Oxidation energy of Al2O3 and RuO2 can be reduced, In order to reduce the structural stability.Among them, the Al2O3 structure stability significantly decreased.At the same time, the alloying of W can reduce the structure stability of Al2O3 Within the RuAl alloy matrix system. Blocking the formation conditions of oxidation process in the generation, reduce the formation of surface perpendicular to the interface of Al2O3, the transverse direction the surface interface on Al2O3 oxide layer growth, the formation of Al2O3 continuous dense oxide layer, improve the oxidation resistance of RuAl.