Rubber and plastic coaxial combined seal is the main structure form of the reciprocating cylinder seal.The material structures of products were usually imitated the imported products.By the introduction of the golden section method in the structural design, the problem of selecting main parameters in the structural design of the coaxial combined sealing products was solved effectively.The designed products are equivalent to the products from abroad in reliability, effectiveness and durability, which provides reference for the structural design of such kinds of products.