Objective: The paper analyzes the characteristics and cost structure of extremely expensive case enrollment, and provides the scientific basis for targeted enrollment control. Method: 1468 extremely expensive cases from a tertiary hospital in Anhui Province from January to October 2022 were selected for DRG evaluation. The enrollment characteristics of extremely expensive cases in DRG were analyzed, and the grey correlation analysis method was used to determine the correlation between each sub-item cost and the total hospitalization cost. Result: Extremely expensive cases have longer hospitalization time, more serious complications/comorbidities, higher difficulty coefficient of the disease group, more insufficient clinical understanding of DRG, and the strongest correlation between consumables and total hospitalization costs. Conclusion: It is recommended to pilot the linkage of point-to-point department warranty, with a focus on the use of high-value consumables, and to strengthen audits of extremely expensive cases and special disease discussions.