A polyurethane polyol dispersions of two-package waterborne polyurethane have been successfully synthesized with diethanolamine (DEA) as the blocking agent for introducing hydroxy-terminated on to the end-NCO polyurethane prepolymers, which were prepared beforehand with isophorone diisocyanate (IPDI), polyether binary alcohol (N210), dimethylol propionic acid (DMPA), and trimethylolpropane(TMP) as the main raw materials. The properties of the dispersions and films such as gloss, hardness, solvent resistance, water resistance were significantly affected by the amount of DMPA, TMP, hydroxy contents and the ratio of dispersions to curing agents. The optimum performance was obtained with the content of DMPA, TMP and DEA reaching 6%～6.5%, 3%～5% and 7.61% respectively, and the ratio of curing agents to dispersions being 1.5～1.7. Furthermore, the synthetic process of the polyol dispersions and the 2K-WPU films were characterized by multiple devices such as FTIR and SEM.