Polyvinyl alcohol (PVA) is a colorless, non-toxic, non-corrosive, biodegradable water-soluble organic polymer. At present, in addition to being the raw material of vinylon, PVA is widely used in textile sizing, coatings, adhesives, emulsifiers, films and other industrial fields. However, the PVA molecule contains a large number of hydroxyl groups, resulting in poor water resistance and stability of PVA, which affects its application. In the application of chemical fiber industry, PVA has disadvantages such as skinning, foaming and insufficient adhesion to fibers. Therefore, chemical modification methods are generally used to improve its water resistance. The modification of PVA mainly uses the chemical reactivity of vinyl acetate double bonds, ester groups and hydroxyl groups after alcoholysis to change the side chain groups or structures, and introduce other monomers to become PVA-based copolymers; Other functional groups that change the chemical structure of PVA macromolecules.