Waterborne polyurethane/polyacrylate emulsion (WPUA) was synthesized with poly-caprolaclone glycol (PCL), isophorone diisocyanate (IPDI), 2,2-dimethylol butyric acid (DMBA), methyl methacrylate (MMA) and butyl acrylate (BA). Glycidyl methacrylate (GMA) and allyloxy hydroxyl propanesulfonic salt (AHPS) were introduced to the waterborne polyurethane/polyacrylate system and a stable epoxy-modified waterborne polyurethane/polyacrylate (EPUAS) composite emulsion had been obtained. The structure, morphology and properties of polyurethane/polyacrylate emulsion and films were characterized by fourier transform infrared spectroscopy (FTIR), transmission electron microscopic (TEM)，X-ray diffraction analysis (XRD) and thermogravimetric analysis (TGA). The amount of GMA on properties of the polyurethane/polyacrylate emulsion and films were discussed. The results showed that EPUAS emulsion shows a core - shell structure, with the increase of w (GMA) from 1 % to 4 %, the thermal stability of the film were improved, the tensile strength gradually increased from 6.8 to 12.3 MPa, elongation at break reduced from 12.2 % to 6.6 %, the degree of crosslinking increased from 60.1 % to 81.7 %, the particle size of the emulsion waw increased from 198 nm to 273 nm, and with the w (GMA) at 4 %, the water absorption, solvent absorption rate of EPUAS film each was fallen to 7.2 %, 16.3 % , whose overall performance achieved the best.