We performed molecular dynamics (MD) simulations to investigate anionic surfactant sodium dodecyl benzene sulfonate (SDBS) adsorption onto a silica surface from solution. Various water phases of different thickness were constructed to investigate the difference between the solid/liquid and the air/liquid interface. We found that surfactant molecules adsorbed on silica surfaces within a short simulation time and they formed a surfactant layer via an interaction between the hydrophobic alkyl chain and the SiO2 surface. With an increase in water phase, one hemi-cylindrical micelle with a hydrophobic core formed on the SiO2 surface when a large amount of surfactant molecules adsorbed. The potential of mean force potential between the polar head of the surfactant and Na + ions or water molecules shows that the dissociation energy barrier is much larger than the combination energy barrier leading to more Na+ ions gathering around the polar head and fewer Na+ in solution. SDBS and water molecules can form complexes through H-bonding at the air/liquid or solid/liquid interface. Simulation results show that molecular dynamics can be used as an adjunct and can provide necessary information for microstructural property experiments.