The backside polishing quality of silicon-based infrared devices directly affects the performance parameters of the chips, and the cleaning treatment after polishing will also affect the reliability of subsequent processes. Cleaning of particles adsorbed on the surface of materials is a hot topic in current research. The cleaning effect of anionic surfactant (sodium dodecyl sulfate (SDS)) on silicon wafer particles after silica sol polishing is explored, and the cleaning mechanism is deeply analyzed using molecular simulation methods. The results show that when the concentration of SDS is high, a bilayer adsorption morphology can be formed on the surface of SiO₂ particles, and a negative charge state is presented on the outermost layer. This forms an electrostatic repulsion force with the negative charge on the surface of the silicon wafer in an acidic environment, thereby effectively cleaning the SiO₂ particles.