Linear organoalkoxysilane-based RAFT agent functionalized polydimethylsiloxane (RAFT-PDMS) has been prepared for the first time via co-condensation of a new organoalkoxysilane based RAFT agent (RAFT-Agent), 2-((methyldimethoxysilyl)propyl)carbontrithio-2-methyl-propanoicacidmethylester, with diethoxydimethylsilane (DDS) in an aqueous acidic solution. The RAFT-Agent and RAFT-PDMS was confirmed by FT-IR and ¹H NMR spectroscopy techniques. The obtained RAFT-PDMS was used to prepare the silicone-modified polyacrylate anti-graffiti emulsions via RAFT polymerization with functional monomers. The living character of RAFT polymerization of RAFT-PDMS and the narrow molecular weight distribution of the polymerization product were confirmed by GPC. The transformation of the particle state from a small micelle structure to a spherical core-shell micelle structure during polymerization was verified by TEM and dynamic light scattering analysis. Moreover, DSC and TGA analysis disclosed that increasing the content of RAFT-PDMS can reduce the glass transition temperature and improve the thermal stability of the resin. Finally, the effect of RAFT-PDMS on the surface morphology and properties of coatings were examined by SEM and contact angle. These experimental results suggest that increasing the content of RAFT-PDMS increases the surface porosity of the coating film and thus enhances its hydrophobic properties.