Abstract: In this article, one-step process was used to prepare polyurethane prepolymer, which was then blocked by pentaerythritol triacrylate and neutralized by acetic acid to obtain cationic curable polyurethane resin. The structure of the resultant was characterized by FTIR and 1H-NMR; the effect of neutralization degree, content of N-methyl diethanolamine on the emulsion and UV-curable varnish properties were studied by particle size analysis, contact angle and centrifugation testing. The results show that the cationic waterborne polyurethane resin exhibits excellent emulsification performance, acid and alkali resistance, alcohol resistance and water resistance when the neutralization degree is 90% and the amount of N-methyl diethanolamine is 6 wt.%.