To investigate the adsorption mechanism of heavy oil on clay mineral surface during surfactant flooding, the microscopic mechanism of heavy oil and surfactant on montmorillonite surface under different temperatures can be explained by molecular dynamics simulation. Based on the four components (SARA) of heavy oil and sodium montmorillonite, the molecular dynamics simulation of the adsorption process is carried out after the water phase adsorbent containing surfactant molecules is added into the adsorption system. It shows that cationic surfactant tends to adsorb on the surface of montmorillonite and occupy more adsorption area, which makes the heavy oil molecules tend to separate from the surface of montmorillonite. The non-ionic surfactant does not show a tendency to adsorb towards the surface of montmorillonite during the relaxation process. Non-ionic surfactant has a high self-diffusion coefficient and thus diffuses in the adsorbent environment. High temperature disperses asphaltene aggregation nuclei in heavy oil, which facilitates heavy oil to flow away from the montmorillonite surface. However, high temperatures can also cause some surfactants more adhesion to the montmorillonite surface, resulting in surfactant loss. This study provides theoretical support for adjusting temperature and surfactant types during surfactant development and enhancing oil recovery of sensitive heavy oil reservoirs.