For the current problems in boundary modeling of DEM, a 3-D DEM boundary modeling software combined with VC++ platform, MFC libraries and Access database was developed. It integrated with the UG software and the 3-D DEM analysis software. Taking the cell wheel feed as an example, there was good agreement by designing the CAD model and comparing the 3-D simulation results of its working process with the experiment results. The results were proved to be feasible and effective.