In this paper, the adsorption behavior of polyoctadecyl acrylate (POA) in model crude oil on the surface of nano⁃SiO2 particles modified by methyl was investigated by performing molecular dynamics (MD) simulations. The adsorption model of model crude oil including POA molecule on the surface of nano⁃SiO ₂ particles was constructed. The model crude oil consists of asphaltene, resin, aromatic hydrocarbons and alkanes. The surface of nano⁃SiO ₂ particles was modified with three different degree of methyl. Several parameters such as the adsorption energy, relative density distribution, the mean square displacement and radial distribution function were analyzed. The results show that the unmodified surface is firstly adsorbed by asphaltene of strong polarity while the surface of 100% methyl⁃modified is firstly adsorbed by n⁃alkanes. The surface of 50% methyl⁃modified particles is firstly adsorbed by aromatic hydrocarbons. The results also indicate that the surface of 50% methyl⁃modified particles is not only more conducive to the stable adsorption of POA molecules, but also conducive to POA molecules to form a better adsorption configuration. What’ more, on the surface of 50% methyl⁃modified particles, the interaction between POA molecule and C ₂₄H ₅₀ molecules is stronger, and the distribution of C ₂₄H ₅₀ molecules is more aggregated. Finally, the study of this paper provides a method for studying the mechanism of pour point depressants composed of polymer and inorganic nanoparticle and provides theoretical guidance for the experimental modification of nanometer particles in nano⁃hybrid pour point depressant.