When the surface metallization of ceramics is applied to ceramic-metal sealing, in order to obtain a dense and firm bond, first of all, there should be good wetting between the sealing agent and the metal and ceramics, and there should be a certain chemical reaction mechanism in the meantime, which can form a continuous, chemically combined transitional tissue layer. It is neither purely physical adsorption, nor will it lose its respective functions due to excessive erosion. Second, the coefficients of thermal expansion of ceramics and metals bonded to each other should be as close as possible. The commonly used metallization method is to first make a transition metal layer (Mo,Ti, etc.) on the ceramic, and then plate a highly conductive metal layer (Ag, Au, Ni, Cu, etc.).