In this paper, a new type of nano-SiO2/silicone-acrylate emulsion composite coatings were synthesized through the modification and dispersion of nano-SiO2 mixed with waterborne resin, dispersant, etc., and successive compounding with silicone-acrylate emulsion. The effects of dispersant concentration, PH value and the addition of waterborne resin on the dispersion stability of the nano-SiO2 aqueous suspension were explored through infrared spectrum, X-ray diffraction techniques and sedimentation test, as well as the influence of thickener and defoamer agent on the performance of the composite coatings. It was found that the nano-SiO2/silicone-acrylate emulsion composite coatings had good properties of weather resistance, anti-abrasion, acid and alkaline resistance and water resistance and so on, which could effectively improve the durability of concrete. So they can be widely used in surface protection of hydraulic constructions.