Objective: Taking a sample hospital as an example, this study explores the effect of establishing a business-finance integration system and optimizing supporting management systems to promote cost reduction and efficiency improvement in hospitals, in order to provide optimization solutions and implementation pathways for business-finance integrated management in other public hospitals. Methods: A business-finance integration system was developed through data center, accounting center, and control center, and supporting application and management systems were designed accordingly. The thyroid surgery department of the sample hospital was selected as the research subject. Differences in DRG capability, DRG efficiency, and CMI before and after implementing business-finance integration measures were analyzed using Excel 2010 and SPSS 26.0. Results: A total of 2247 hospitalized patients from the thyroid surgery department were included. The results showed that after implementing business-finance integration measures, the number of disease groups increased, while medical treatment days, total hospitalization costs, surgical fees, material costs, western medicine fees, and laboratory fees decreased, with statistical significance (P < 0.05). The overall CMI value remained stable. Conclusion: Currently, business-finance integration has achieved preliminary success in cost management and service expansion. However, the system shows limited effectiveness in promoting technological innovation or improving CMI. Achieving high-quality development while reducing costs and improving efficiency is to be explored .