Objective: The paper analyzes the relationship between medical service price reform and DRG payment reform, explore the synergistic mechanism between the two, and provide a reference for government decision-making and high-quality development of hospitals. Methods: Based on the data of 610624 patients from the sample hospitals from 2018 to 2022, the paper applied the degree of structural variation and grey relation analysis method to quantitatively analyze the degree of structural variation, the contribution rate of the degree of structural variation, and the correlation degree of hospitalization expenses. Results: Since 2018, average hospitalization expenses of the sample hospitals have shown a fluctuating downward trend, with an average annual decrease of 1.81%. Among them, the proportion of drug fees has been decreasing year by year, with the highest contribution rate to structural changes. The cost of treatment and surgery has relatively increased, and the contribution rate is inferior to drug fees. However, the proportion of laboratory fees and inspection fees has relatively increased, while the proportion of sanitary material fees remains basically unchanged. Conclusion: The medical service price reform and DRG payment reform promoted the optimization of the medical expense structure of hospitals. It is necessary to strengthen the synergy of the two, strengthen the complementary relationship, further optimize the revenue structure of hospitals, and promote high-quality development of hospitals.