In this paper, the high temperature oxidation treatment of Kovar alloy was carried out under different oxidation atmosphere conditions, and the optimum oxidation process of Kovar alloy was optimized. The wetting test and sealing test were carried out with borosilicate glass. At the same time, the oxidation composition and sealing interface were analyzed by XRD, XPS, SEM, EDS and other analytical methods. The results show that Fe, Co and Ni elements all participate in oxidation reaction at high temperature, and the oxidation dynamics of Kovar alloy follow the parabolic rule. The optimal oxidation process of Kovar alloy is: oxidation temperature 850 ℃, oxidation time 11.7 min, N₂ flow 1 L/min, and dew point 30 ℃. After oxidation treatment in different atmospheres, the hermeticity of Kovar alloy and glass sealing changes little. The tensile strength of glass and Kovar alloy with surface oxide of Fe₃O₄ is the highest after sealing.