A series of stable double-terminated UV reactive cationic waterborne polyurethane dispersions was synthesized, while the structure was confirmed by infrared spectroscopy,laser particle size analysis and free NCO root titration; modified by co-monomerhydroxyethyl acrylate with the UV radiation fast curing, the influence of hydroxyethyl acrylate proportion and the polyurethane’s nNCO/nOH(R value) to the thermal properties, mechanical properties and yellowing of the product was investigated. The investigation illustrated the UV-curable cationic waterborne polyurethaneacrylate film effectively forming a semi-interpenetrating network system to achieve rapid curing coating.The results showedthe product cured by WPU dispersion of R=1.5 mixed with equimolar HEA obtained lowyellowing, the maximum breaking strength, high elongation at break, high thermal decomposition temperature, high crystallization temperature of hard segment, low glass transition temperature of soft segment, high degree of phase separation, better overall performance.