Objective: To analyze the changes of average inpatient cost before and after medical-pharmaceutical separation reform and medical consumables linkage reform in the DRG pilot hospitals in Beijing，and to explore the effects and problems of these two rounds of medical reform. Methods: The inpatient cost data of Beijing DRG pilot hospitals from January 2017 to December 2019 were collected. The instantaneous and long-term trend changes of the average cost of inpatients were analyzed based on the segmented regression model of interrupted time series. Results: The results showed that the average cost of inpatients remained stable on the whole，and there was a rising trend after a short-term decline. The proportion of drugs and materials per person in average cost per person decreased significantly，and the proportion of surgical costs in hospitalization costs increased significantly. Conclusion: These two rounds of comprehensive medical reforms had a significant intervention effect on the optimization of the internal structure of the hospitalization cost in the DRG pilot hospitals in Beijing，and the value of the technical labor of the medical staff was gradually reflected. However，in the long run，the average cost per person was still growing. It was needed to continue to pay attention to the reform of the drug and consumable costs.