Abstract: Stone cultural heritages hold significant historical value, but they are subject to natural erosion, making their protection urgently. Silicone-acrylic emulsion, with its excellent weather resistance, transparency, hydrophobicity, and mechanical properties, can serve as a water-based coating for the protection of cultural relics. This study used semi-continuous soap-free seed emulsion polymerization to prepare an organic-silicon modified polyacrylate emulsion. The effects of reactive emulsifier, organic silicone, soft and hard acrylate monomers, and solid content on the comprehensive properties of the emulsion and latex film were investigated. The optimal reaction conditions were determined as follows: the dosage of reactive emulsifier was 3.75%, the dosage of organic silicone monomer was 2.50%, the mass ratio of butyl acrylate to methyl methacrylate was 4∶4. The prepared emulsion exhibited stable performance and could be stored for an extended period. The latex film demonstrated excellent weather resistance, transparency, water resistance, acid and alkali resistance, and mechanical properties, which could be effectively applied to the conservation of stone cultural relics.