The work aims to improve the oxidation resistance of the molybdenum electrode in the process of heating in the empty kiln. Oxidation-resistant glass coatings with different Y2O3 contents were prepared on the surface of the molybdenum substrate. The oxidation resistance of the coatings was tested at 800 ℃, 1000 ℃ and 1200 ℃. The microstructure, composition and phase of the as-prepared specimens were tested by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In addition, the differential thermal analysis (DTA) was carried out to the coating powder by thermal analyzer. The softening temperature of silicate glass continuously decreased, and the peak of crystallization exothermic got lower and lower with the increase of the Y2O3 content. The coating surface with 10% and 20% Y2O3 was complete and dense. The weight increased in the first hour under the oxidation condition of 1200 ℃, and then tended to be stable with the heating time. The coating surface with 30% Y2O3 showed a dense structure but partially spelled which resulted in the significant weight loss during oxidation. After oxidized at 1200 ℃, the Y2O3-glass coating with 10% Y2O3 shows excellent oxidation resistance performance, with intact surface and less increased weight. The cross-section of the coating is composed of transition layer, intermediate layer and outermost layer. The phase composition of the transition layer, the middle layer and the outermost layer is mainly MoO2/MoO3, BaMoO4 and SiO2, respectively. The oxidation resistance mechanism of the coating is a mutual melting reaction type protection mechanism and an inert melt film shielding type protection mechanism.