Solubility parameter is used as an evaluation index for compatibility of asphalt components. The rationality of the model of each component of asphalt is verified. The asphalt molecular model was established after the proportion of asphalt component was determined by the four component test, and the asphalt stabilized structure was obtained. 1nm width of crack in the asphalt stable phase was preset, the variation of density, energy and mean square displacement of the asphalt molecules at different temperatures were studied by molecular dynamics simulation. The results show that before the equilibrium state, the density and energy change significantly, asphalt has sub diffusive behavior，The mean square displacement of asphalt molecules has a nonlinear relationship with time, indicating that the mean square displacement of asphalt molecules is nonlinear secondary diffusion process, and when reaching equilibrium state, the energy and density stability, asphalt self diffusion velocity and time have good linear correlation, the molecular diffusion rate increases with the increase of temperature, which shows that the simulation of asphalt molecular self healing behavior is feasible using the research methods and ideas of molecular dynamic simulation.