2-Hydroxyethyl acrylate and pentaerythritol triacrylate were used to synthesis two functionality waterborne polyurethane acrylate (WPUA2) and six functionality waterborne polyurethane acrylate (WPUA6). The structure and properties of PUA were analyzed by means of FTIR, particle size analyzer and TG. The study found that, compared to use low functionality WPUA2 UV curing polyurethane acrylate (PUA) film, the PUA gel content of cured film improved more than 20%, the water absorption rate decreased 30% when adding monomer or using multifunctional WPUA6; While the quality loss 10%, the temperature increased 82 °C. Improved the prepolymer functionality can effectively improve the coating crosslinking density and heat resistance, and possess similar application effect with adding active monomer.