Abstract: Two different long-chain silanes, hexadecyltrimethoxysilane (HDTMS) and tridecylfluorooctyltriethoxysilane (PFTDS), were used to modify nano titanium dioxide (TiO₂), and the modified TiO₂ nanoparticles were in-situ polymerized with polysiloxane prepolymers to prepare composite coatings through a two-step spraying method. The dispersion of modified nanoparticles was significantly improved, and the corresponding composite coatings formed a uniformly distributed rough structure on the substrate. Only a 20% (mass fraction) loading of the modified TiO₂ could make the composite coating exhibit superhydrophobicity, exhibiting excellent self-cleaning performance, corrosion resistance, and UV photocatalytic performance. The material had broad applications in fields such as construction, automobiles, and ships.