This study proposes a rational method for modelling ballast in tracks based on the discrete element method (DEM) approach. To simulate a ballast consisting of a group of gravels, it is essential to use the discrete element method. The ballast comprises randomly arranged gravels of unspecified shapes, and requires multiple steps and a separate house code for implementing the ballast. In this study, a simplified ballast analysis model using the parallel bond method (PBM) is proposed and verified through comparison with design standards. Additionally, case studies are conducted to investigate the effect of particle size distribution and micromechanical parameters on the simulation results.