According to the mutual relations of standard costing,activity-based costing and inner transfer pricing, this paper explores systematically the approaches of the integrations of the above three in the large or medium enterprises that carry out decentralized management. Further, we raise three models as external report model, internal decision model and social contribution model, based on the financial accounting, managerial accounting and incremental accounting respectively. Finally, we investigate the principle of stratified application of the integration of standard costing, activity-based costing and inner transfer pricing, in the perspective of practice. The formula is presented that decomposes the inner transfer pricing, budgets the comprehensive cost and converses the variable cost & materiel cost into the manufacturing cost.