The conversion coating product using silane coupling agent alone has a thin conversion film and poor corrosion resistance. Although it can improve the bonding force between the coating and the metal substrate, the metal substrate is easy to rust before coating the coating. This layer of conversion coating is difficult to meet the anti-rust requirements between processes, so it is necessary to add other film-forming substances for compounding to improve the performance of the conversion coating in all aspects. The film-forming substances that can be added include fluorozirconic acid, borate, and molybdic acid. salt etc. Since these substances are mostly water-soluble inorganic substances, they cannot be directly miscible with silane coupling agents, so water is needed as a carrier for the coexistence of silane coupling agents and inorganic substances, which requires adding oil-soluble silane coupling agents to Hydrolysis in water. If the hydrolysis treatment is not carried out, the silane coupling agent will float in the aqueous solution like small oil beads and cannot be uniformly dispersed in the aqueous solution, which will greatly reduce the effect of the silane coupling agent.