Objective To evaluate the quality management model of regionalized Central Sterile Supply Department based on risk classification, including the quality changes before and after the implementation and the incremental resource investment situation. Methods This before-and-after quality-improvement study included 460 standard instrument-processing batches from the same six partner institutions. Among them, the pre-implementation phase was March-October 2024 and the post-implementation phase was January-August 2025 (230 batches each). The differences in qualified rate of equipment cleaning, standardization of process execution, incidence of adverse events, and service satisfaction rate before and after the implementation were compared. Results Institution source, instrument category, and risk-grade distributions were comparable between phases (all P＞0.05). Qualified rate of equipment cleaning was higher after implementation than before implementation (P＜0.001). Classification accuracy, packaging compliance, and sterilizationoperation compliance all increased than before implementation (all P＜0.001). The overall incidence of adverse events decreased from 13.04% to 3.91% (P＜0.001), and overall service satisfaction rate increased from 87.83% to 96.96% (P＜0.001). Conclusion After the implementation of the regionalized management model based on risk classification, the qualification rate of equipment cleaning, the standardization of process execution, and the service satisfaction rate all improved, and the incidence of adverse events decreased. This study can provide a feasible implementation path for improving the quality of regionalized sterile supply.