Objective: The paper studies the long-term trend of changes in the cost of percutaneous coronary intervention (PCI) before and after coronary stent centralized procurement, so as to evaluate the implementation effect of the centralized procurement policy, and propose policy recommendations. Methods: We extracted the cost data of the first page of medical records of discharged patients undergoing PCI in a tertiary comprehensive hospital in Ningbo City of Zhejiang Province from 2019 to 2024. The disease cost, composition ratio, and cost correlation degree were analyzed through structural change degree and grey correlation analysis, and statistical methods were used to analyze the changes in various costs before and after centralized procurement. Results: A total of 14476 discharged patients were included. The median cost of PCI before coronary stent centralized procurement (2019-2020) was 41559 yuan, which decreased to 28988 yuan in the initial period of centralized procurement(2021-2022), and further decreased to 25730 yuan in the long-term period of centralized procurement(2023-2024), showing a continuous downward trend with statistical significance (J-T=-38.63, P<0.001). From long-term data, it can be seen that after the implementation of the centralized coronary stent procurement policy, the structure of PCI disease expenses has remained basically stable, and the contribution rate of consumables to the structural changes of disease expenses is the highest at 50.00%. The highest correlation between drug costs and disease costs is 0.825. Conclusions: The policy of centralized procurement of coronary stents has a sustained effect on reducing the cost of PCI, and has a positive significance in achieving healthcare reform goals such as alleviating the "high cost of medical treatment" and increasing the proportion of medical service income. However, the increase in the proportion of medical service income mainly depends on the reduction of consumable costs. It is suggested to take advantage of the opportunity brought by centralized procurement to timely promote the reform of medical service price adjustment, scientifically formulate disease payment standards according to technical difficulty and risk, in order to avoid limitations on innovative technologies in clinical application.