The core-shell acrylic emulsion was prepared by semicontinuous seeded emulsion polymerization with acrylic monomers as the main raw materials and the octafluoropentyl methacrylate (OFPMA) as modified monomers. And the influence of OFPMA on the hydrophobicity, thermal stability and mechanical properties of acrylic emulsion film was investigated. Fourier transform infrared spectroscopy (FTIR) analysis and X-ray photoelectron spectroscopy (XPS) all indicated that the OFPMA was successfully introduced to the acrylic emulsion. TEM image shows that the emulsion particles have a core-shell structure. The addition of OFPMA reduces the water absorption rate (3.2 %) of the coating film and improves its water resistance. Contact angle of coating surface increased from 80.7° to 90.7°. Moreover, TGA curves showed that the addition of OFPMA increased the initial decomposition temperature of the polymer from 355 ℃ to 370 ℃. Additionally, with the addition of OFPMA, the mechanical properties of modified polymers were also improved compared to pure acrylic resin. The application of the core-shell structure reduces the amount of fluorine-containing acrylic monomers, reduces environmental pollution, and improves economic benefits. This study provides a kind of environmentally friendly waterborne acrylic resin and a simple method for optimizing the performance of waterborne resins.