Toluene diisocyanate(TDI), polyethylene glycol(PEG), double-propionic acid(DMPA), hydroxyethyl methacrylate(HEMA) and other raw materials were used to synthesis UV-curable waterborne polyurethane, and the effect of the synthesis condition on the particle size of the emulsion was investigated in this paper. The structure of the polyurethane was identified by infrared spectroscopy (IR), thermal decomposition properties was measured through the thermogravimetric(TG). The results showed that, the target product is expected waterborne UV polyurethane by IR. With DMPA content increasing, the particle size decrease, stability and appearance of the emulsion turn better. With the mole ration of PEG/DMPA decreasing, adhesion and water absorption of the film increase. TG analysis indicates that the thermal decomposition performance of the Waterborne UV Polyurethane （WPUA） is excellent.