Establish the enterprise internal cost management mode which combines the enterprise internal cost with the market mechanism. The Enterprise's external market target is transformed into the enterprise's internal operation target, and the enterprise's internal operation target is transformed into the employee's benefit. The establishment of this internal market chain is achieved through business process reengineering, that is to change the past function management into process management, establish a new business process, so that all the activities of the enterprise start with the order. The internal market chain of an enterprise is a closed-loop structure composed of customer order information, Marketing Department, Product Assembly department, product parts production department, raw material purchasing department, Accounting Department, R & D Department, raw material supplier, etc. , some enterprises still follow the traditional cost management model because of the needs of their development model. Although the model is somewhat backward, it can still be applied to enterprises,