Vacuum brazing of glass to Kovar alloy was carried out at 670~700°C using Cu-Ni-Sn-P brazing alloy. The holding time ranges from 5min to 30min. The shear stress was tested to evaluate the mechanical property of the vacuum brazed joints. The results showed the maximum shear stress was 11.6MPa when the brazing temperature was 680°C and holding time was 10min. In accordance with the welded structures, the finite element (FE) model of glass-to-metal brazed joints was established. As result, the shear tests on the lap joints in conjunction with FM analysis were used to optimize the glass-to-metal brazing technology. The above results provide the basis of design against damage and reliable estimation of glass-to-metal seals.