The multi-bridge high-pressure waterjet cutting machine greatly improved cutting efficiency, and also made one-off processing of large workpiece possible. In order to further improve the efficiency of this system, this paper have put forward a drawing treatment—using ObjectARX development kit to do secondary development of AutoCAD drawing. Through customized menu commands of AutoCAD to call ObjectARX application, thus achieve automatic drawing segmentation, namely assigned equivalent workload as possible for each cutting head to increase the simultaneous work time of cutting heads and improve efficiency. At last, experiments were taken to verify the feasible of this method.