Isocyanate group-terminated polyurethane prepolymer(PU-Si) was synthesized by polyether polyols (N210), IPDI, hydroxyl silicon, the waterborne curing agent modified by polyurethane contained silicon was prepared using PU-Si , epoxy resin (E-51)and TEPA-660a.The structure and properties of polymer was characterized by IR, SEM,TG and water contact angle measurement;and studied the effect of PU-Si content on emulsifying properrty of curing agent，the mechanical properties, thermal properties, impact fractured surfaces and water absorption of the cured film. The results show that When the PU-Si content is18%, the cured film has the best comprehensive performance, impact strength is 22.4KJ.m-2,tensile strength is 44.7MPa, the characteristic decomposition temperature at 5% and 50% mass loss is 205℃ and 373.8℃,water contact angle is 96.8? water absorption is 24h is 1.35%,the toughness and heat resistance both have well performance compared respectively to pure epoxy.