In this paper, R2O-RO-Al2O3-B2O3-SiO2 based sealing glass-ceramics with diopside as main crystalline phase was designed and prepared for the sealing of solid oxide fuel cell (SOFC). The effect of Na2O content (0%～10%, mole fraction) on coefficient of thermal expansion (CTE), crystallization and sintering wetting property of sealing glass was analyzed, and the sealing interface between glass and SUS403 stainless steel after high temperature and long time heat treatment was characterized. The results show that Na2O can significantly improve the thermal properties of glass, the prepared glass samples can be obtained as glass-ceramics with main crystalline phase of diopside (CaMgSi2O6) after heat treatment in sealing temperature range. With the increase of Na2O content, the crystal phase content of main crystal phase diopside is different, and coefficient of thermal expansion of glass-ceramics increases from 8.22×10-6 K-1 before crystallization to 11.79×10-6 K-1, which can meet the thermal expansion match of SOFC sealing. When the Na2O content is greater than or equal to 8% (mole fraction), the crystalline phase of high expansion calcium akermanite (Ca2MgSi2O7) is precipitated in glass, which is not conducive to sealing. After sealing 4% (mole fraction) glass sample with SUS403 at high temperature for 100 h at 850 ℃, the sealing interface is dense and firm without air pores. There is a Cr2O3 layer at the interface and a thin layer of diopside which is denser than glass sealing body. The existence of these dense layers is beneficial to limit the diffusion of Na+ from sealing glass to interface.