Abstract: To investigate the behavior of multi-layer graphene (MLG) and other graphene assemblies effectively, a coarse-grained molecular dynamics (CG-MD) method was developed, which conquers the limitations of experimental observations and full atom simulation to some extent. The CG-MD method based on Tersoff potential was used to simulate large scale graphene. The coordinates of the model were needed in the process of computation, which greatly reduced the time of modeling. The comparison between the results of full atom model and CG-MD model was made. It is proved that the CG-MD model can predict the tensile behavior of MLG accurately and it has great significance to producing graphene fiber with high performance.