Objective To analyze the medical resource consumption of healthcare-associated infection (HAI) in patients in different groups of disease diagnosis-related grouping (DRG)based on the DRG payment model, provide reference for optimizing prevention and control of HAI as well as resource management. Methods Medical records and DRG-related indicators of discharged patients from a municipal hospital in Sichuan Province from January 1 to December 31, 2024 were analyzed retrospectively. Medical resource consumption of patients in HAI group and non-HAI group was compared. Differences in average length of hospital stay and average expense per hospitalization between two groups of patients were analyzed using stratified analysis. Results In 2024, HAI incidence of discharged patients in DRG management in this hospital was 1.57%. There were statistically significant differences in age, gender, admission and discharge ways between the HAI group and the non-HAI group (all P<0.05). The main HAI sites were lower respiratory tract, surgical site, urinary tract, and blood. The time consumption index (1.63 vs 0.85), average length of hospital stay (21.00 vs 5.00 days), expense consumption index (1.53 vs 0.92), ave-rage expense per hospitalization (44 700 vs 7 300), and multiple expense in HAI group were all higher than those in non-HAI group (all P<0.05). The consumption of medical resources for bloodstream infection was relatively higher. Patients with HAI were mostly concentrated in the groups related to acute leukemia with major complications or comorbidities (MCC), intracranial or craniotomy surgery with MCC, tracheotomy with mechanical ventilation for 96 hours, as well as gastric, esophageal, and duodenal surgery. The average length of hospital stay and average expense per hospitalization of patients in HAI group were both higher than those in the non-HAI group, differences were statistically significant (both P<0.05). Conclusion HAI significantly increase the consumption of medical resources. Based on DRG analysis, key disease groups for infection prevention and control can be further identified, and the consumption of medical resources can be more accurately and precisely evaluated, thereby optimizing the allocation of medical resources and improving hospital operational efficiency.