Objective To investigate the clinical effect of SGLT2 inhibitor in the treatment of type 2 diabetes mellitus complicated with heart failure. Methods A total of 168 patients with type 2 diabetes and heart failure who were treated in First People's Hospital of Xinmi were selected, and randomly divided into control group and study group with 84 cases in each group. Both groups were given conventional heart failure drug treatment, and the study group was given SGLT2 inhibitor therapy on this basis, and both groups were given continuous treatment for 6 months. Before and after treatment, the blood glucose and serum ST2 and NT-proBNP levels in the two groups were detected, and the cardiac function indexes were monitored, and the incidence of adverse events during treatment and follow-up was compared between the two groups. Results After treatment, the levels of blood glucose FBG, 2h PG and HbAlc, the levels of ST2 and NT-proBNP in the two groups were significantly decreased compared with those before treatment, and compared with the control group, the study group had a more significant decrease (P<0.05). After treatment, the levels of LVEF, SV and 6MWD in the two groups were significantly higher than those before treatment, and the increase in the study group was more significant than that in the control group (P<0.05). Conclusion SGLT2 inhibitors in the treatment of type 2 diabetes mellitus complicated with heart failure can effectively reduce blood glucose and serum ST2 and NT-proBNP levels, and improve cardiac function in patients.