Abstract: The phenomenon of chloride ion corrosion in concrete during freeze-thaw cycles was addressed. A silicone-acrylic emulsion (TSA) was synthesized via semi-continuous seeded emulsion polymerization. TES served as the organosilicon monomer, while methyl methacrylate, butyl acrylate, and acrylic acid were used as main raw materials. Nano-SiO₂ was surface-functionalized with octadecylamine (ODA) to prepare modified nanoparticles. Composite coatings were fabricated by physically mixing TSA and ODA-SiO₂. The impact of TES content on TSA emulsion properties was analyzed. The effects of ODA-SiO₂ addition on coating performance, including mechanical strength, hydrophobicity, aging resistance, and corrosion resistancewere examined. The protective mechanisms were also explored. The results indicate that the TSA emulsion prepared with mass fraction 6% TES shows a narrow particle size distribution centered at 122 nm, the glass transition temperature of 4.22℃, and low surface energy. When the ODA-SiO₂ content is mass fraction 2%, the composite coating achieves optimal mechanical properties and the lowest chloride ion penetration of 0.308×10⁻³ mg/(cm²·d). It exhibits high compactness, with the lowest water absorption rate of 3.94%. After application on concrete, the 6 h electric flux is 559.44 C. Following 50 freeze-thaw cycles, the concrete demonstrates a compressive strength loss rate of 17.3% and bonding strength of 1.83 MPa, confirming effective corrosion protection for concrete.