Objective To evaluate the effect of day surgery with diagnosis-related groups (DRG) evaluation indicators. Methods The inpatients undergoing surgery in Beijing Tongren Hospital of Capital Medical University between March and September 2022 were enrolled in this study. The medical quality, medical efficiency, hospitalization cost, DRG insurance payment and other DRD-related indicators were retrospectively collected and compared between day surgery patients and non-day surgery patients, and the average length of hospital stay and hospitalization costs were compared between the two surgery modes within DRGs. Chi-square test was used for enumeration data, and t-test and Mann-Whitney U test were used for measurement data. Results A total of 29339 day surgery patients and 19019 non-day surgery patients were enrolled. In the day surgery group, the proportions of local patients (71.71% vs. 68.62%), routine discharge (99.93% vs. 99.78%), and class A incisions (99.92% vs. 99.55%) were better than those in the non-day surgery group (P<0.05), and the average length of hospital stay [(1.00±0.00) vs. (6.98±5.00) d] and the average hospitalization costs [(7306.62±4605.73) vs. (24913.97±24623.54) yuan] were lower than those in the non-day surgery group (P<0.05). The top 2 reduction of average length of hospital stay were in the CB49 group and CB39 group, decreasing by 87.45% and 86.24%, respectively. The top 2 reduction of hospitalization costs were in the DC19 group and CC15 group, decreasing by 84.15% and 73.61%, respectively. DRG payment balance of medical insurance in the day surgery group was higher than that in the non-day surgery group (22.95% vs. 5.98%). Conclusions Day surgery not only ensure the medical quality, but also shorten the length of hospital stay and reduce the burden of medical expenses. Day surgery can effectively improve the utilization efficiency of hospital bed resources, it is an effective measure to promote the high quality development of hospital and comply with DRG payment reform.