The work aims to prepare the spherical polymer brushes with silicon dioxide as the core and polymethyl methacrylate as the brush, so as to investigate the properties of spherical polymer brushes when taken as the moisture-proof coating's main film-forming material of the packaging paper. With the technology of "grafting from the surface", the methyl methacrylate spherical brush was generated by initiating the monomer polymerization through the initiator. The structure and morphology of spherical polymer brush were characterized by FTIR and TEM, and the application performance of the spherical polymer brushes treated as the coating film-forming material was investigated. The synthetic spherical polymer brush had good water resistance and still had a low viscosity (64 mPa·s) at a solid content of over 40%. The spherical polymer brush has the application value in moisture-proof coating of packaging paper with high solid content and low viscosity.