Microemulsion polymerization usually refers to the polymerization of submicron monomer droplet dispersion system with stable dynamics through ultrasonic emulsification process and combined action of emulsifier and stabilizer. Compared with common emulsion, microemulsion is a transparent or semitransparent colloidal dispersion system with isotropy, thermodynamic stability and smaller dispersion size. The latex particle size of the polymer microemulsion is 10-100 nm, which has very low surface tension, good permeability, wettability and leveling property. And the film formed by the polymer has good transparency