EVA is prepared by copolymerization of ethylene and vinyl acetate monomers under the action of an initiator. Co polymerization reaction refers to the simultaneous participation of two or more monomers in a polymerization reaction under certain conditions, resulting in the formation of polymers with specific structures and properties. In the manufacturing process of EVA, the ratio of ethylene and vinyl acetate monomers can be adjusted as needed to obtain EVA products with different vinyl acetate contents.