Objective To study the preparation processes of acrylic emulsion used as binder resin of waterborne ink applied on plastic film. Methods The acrylic emulsion was prepared by seed emulsion polymerization technology using polymerisable emulsifiers. The composite emulsion polymer was characterized by Fourier transform infrared ( FTIR) and differential scanning calorimeter( DSC) . Results The water resistance of film was improved when suitable polymerisable emulsifiers were combined in an appropriate way. The water resistance of coating increased with the addition of glycidylsmethacrylate. The water resistance and adhesion of the emulsion coating could be adjusted by changing the ratio of hard monomer ( methyl methacrylate and styrene) to soft monomer ( butyl acrylate) . Conclusion When the content of combined reactive surfactant was 2. 5% of total monomer mass, the mass ratio of soft monomer to hard monomer was 1 : 1, and the content of GMA was 8% , and the emulsion as well as the resulted ink had good adhesion, water resistance of emulsion and ink coating on PET.