Abstract：Objective To investigate the intervention effect of dapagliflozin combined with metformin in patients with type 2 diabetes mellitus.  Methods A total of 96 patients with type 2 diabetes mellitus treated at  Guangzhou Nansha District People's Hospital from January to December 2024 were randomly divided into control group and observation group, with 48 cases in each group. The control group received metformin alone, while the observation group was treated with dapagliflozin combined with metformin. The therapeutic effect, glycemic control and incidence of adverse reactions were compared between the two groups.  Results The total effective rate of the observation group was higher than that of the control group, and the incidence of adverse reactions was lower, with statistically significant differences between groups（χ2＝7.454, 7.448, both P＜0.05）. After treatment, glycated hemoglobin, fasting blood glucose and 2-hour postprandial blood glucose in the observation group were lower than those in the control group; the insulin secretion index was higher and the insulin resistance index was lower, with statistically significant differences（t＝12.114, 12.621, 13.214, 11.213, 10.638, all P＜0.05）.  Conclusion Dapagliflozin combined with metformin is significantly effective in the treatment of type 2 diabetes mellitus and deserves clinical attention.