The wetting and spreading of glass binders on silver have an important influence on the properties of conductive silver paste. Therefore, it is necessary to consider the wettability between glass binder and silver when designing conductive silver paste. In the present work, the wettability of the Bi2O3-B2O3 (-ZnO)/silver system was studied in detail. A high temperature contact angle measuring instrument was used to study the dynamic contact angles of different glass/silver systems. After the wetting test, the microstructure of the surface and cross section of the droplet/substrate was studied. In addition to the bulk liquid usually observed, the precursor membrane was observed near the triphase line. The wetting and spreading of glass melt are mainly controlled by the viscosity of glass melt and the blocking effect of the triphase line. In the process of heating up, the wetting process of glass/silver system can be divided into three stages: incubation stage, temporary equilibrium stage, and rapid spreading stage. The content of zinc oxide has a great influence on the wetting behavior of Bi2O3-B2O3 (-ZnO)/silver systems.