Abstract This paper describes a dynamic control technology of production planning based on modified Bom. Firstly, the modified BOM information is constructed based on the reservation relation after the MRP operation. Then, based on the planning network graph model, the critical task node and its critical path are found, and the running status is monitored in real time. The critical path is modified dynamically, and the method is proved to be scientific and feasible by an example. In this paper, an intuitionistic and dynamically updated plan network chart is generated by the system’s automatic mapping, which is used to guide the production managers in making plans, adjusting plans, reporting progress, and performing other daily work. In addition, the critical path technology is applied to assist the production decision-maker in identifying the key tasks that need the key support, thus further improving the production management and control ability of the enterprise, which has very good social benefits.