Abstract: Borosilicate glass was used as solder, and alumina ceramic sheets were used as substrate. The high-temperature wetting behavior and interfacial bonding properties of glass solder on alumina ceramic substrates were investigated, and the effects of temperature, atmosphere and pressure on the microstructure and properties were analyzed. The results show that the minimum contact angle between 580 ℃ molten glass solder and ceramic substrate under vacuum is 15.54°, and the glass solder and the alumina ceramic substrate have good wettability. Sintered under no pressure at 580 ℃, the bonding strength is the highest with value of 36.38 MPa. According to the microstructure analysis, when the glass solder and the substrates are sintered under vacuum at 580 ℃, there are no obvious bubbles inside the glass solder with good interface combination to ceramic substrate.