Compared with traditional costing, activity-based costing calculates costs down to the activity level, which is more accurate than traditional costing. In the process of cost control, activity-based costing can analyze the cost drivers of each operation and provide management with accurate cost information, so that cost control is not limited to post-event accounting, but runs through product procurement, production, assembly, and debugging. The whole process of product production. Secondly, this article uses Company M as a case to analyze the differences between traditional costing and activity-based costing in the cost accounting and cost control processes. Finally, by using activity-based costing to analyze the entire production process of “J” metallurgical products of Company M, cost control suggestions for Company M are given, so that the problems existing in the procurement process and production process of Company M can be solved.