Objective: To provide the references for the allocation and adjustment of health policy of Beijing in the next step by analyzing the changes in the institutional flow of residents and outsiders for medical treatment expenses and service volume before and after the comprehensive reform of “medical-pharmaceutical separation" and “medical consumption linkage" in Beijing. Methods: Based on A System of Health Accounts 2011 (SHA 2011), a multi-stage stratified cluster sampling method was used to calculate the treatment costs of patients from different medical institutions from 2016 to 2019. Results: From 2016 to 2019 , the community medical and health institutions had the fastest growth in the treatment costs of medical institutions in Beijing and the proportion of treatment costs and service volume showed an upward trend year by year. Residents' treatment costs and outpatient services mainly flowed from tertiary hospitals to community health service institutions. In 2019, the proportion of service volume of inpatient service volume in tertiary hospitals increased from 50.19% to 53.12%,and the cost and service volume of outpatient clinics and inpatients in tertiary hospitals increased slightly. The average cost per visit of non-residents patients in institutions of the same level was higher than that of residents, the difference in the average cost per inpatient visit in tertiary hospitals was gradually decreasing, and the difference in the average cost per inpatient hospitalization in secondary hospitals increased. Conclusion: After the comprehensive medical reforms in Beijing, the flow of treatment costs had been optimized year by year, it had effectively diverted the flow of outpatients from secondary and tertiary hospitals to the communities. The optimization of the flow of outpatients for residents had achieved obvious results. The service capacity building of primary medical institutions should be strengthened. The reform of medical consumption linkage might increase the attractiveness of tertiary hospitals to a certain extent, especially for non-residents patients, and the capital's high-quality medical resources should be allocated reasonably.