Objective: The paper analyzes the results and effectiveness of disease cost management under the reform of DIP payment method, and explores the methods of reducing cost and increasing efficiency to realize fine management of hospitals. Methods: DIP cases of the whole hospital and the Department of Cardiology （one of the key characteristic departments）from 2022 to 2023 were taken as samples, and comparative analysis and Mann-Whitney rank sum test were applied to conduct statistical analysis of the DIP disease cost management from the three dimensions of "hospital-department-disease". Results: In 2023, the enrollment rate of DIP diseases increased, the proportion of extremely high and low-cost cases decreased, the average cost per case and the proportion of drug cost decreased. The average hospitalization cost, comprehensive treatment service fee, drug cost and consumable cost were significantly decreased (P<0.05). The average hospitalization cost, disease score, average length of stay and proportion of drug cost had significant impact on the profit and loss of disease (P<0.05). The medical insurance balance amount of key disease groups was increased with the adjustment of disease structure. Conclusion: Deepening the reform of DIP payment method and strengthening the management of disease cost is conducive to improving the quality and efficiency of hospital medical service and the efficiency of medical insurance funds.