This paper summarized the progress of molecular dynamics simulation applied in the study of small molecular diffusion in food plastic packaging materials and discussed the development of molecular dynamics simulation approach at home and abroad in recent 20 years. Molecular dynamics simulation approach can be used to qualitatively analyze the diffusion behavior of small molecules by building polymer patterns and to calculate the diffusion coefficient. There are still many issues to be resolved in the studies of molecular dynamics simulation applied in the field of food packaging, such as the discrepancy between the calculated diffusion coefficient by the simulation and the actual value as well as the value calculated by emiempirical equation and insufficient application of simulation for composite packaging films.