With IPDI, PCDL,DMPA,TEA,MMA and BA as the basic raw materials, hybrid emulsion of waterborne polyurethane-acrylate(WPUA) was prepared by in-situ emulsion copolymerization method in this paper. The effects of PU content, quality ratio of MMA and BA, the n(-NCO)/n(-OH) and the amount of DMPA on the properties of the emulsion and coating film were systematically studied. The results showed that when the PU quality score was 80%, the initial molar ratio of the -NCO and -OH value was 6.0,using DMPA mass fraction at 5%, and the m(MMA):m(BA) at 4:6, the WPUA hybrid emulsion showed a stable performance.Compared with the bibulous rate of 24.75% of the unmodified PU film,the water absorption of the WPUA film was reduced by 60.4%,reaching to 9.80%,and the tensile strength of the modified film increased by 1.53 times of the PU film,reaching to 28.9MPa.All the results show that the stable WPUA emulsion was prepared,and it exhibits superior performance properties in water resistance and physical and mechanical properties.