Abstract: Objective： To evaluate the clinical efficacy and safety of dapagliflozin combined with metformin in the treatment of type 2 diabetes mellitus. Methods： A total of 104 patients with type 2 diabetes mellitus admitted to the department of endocrinology of our hospital from August 2018 to June 2019 were collected. 2 cases were lost to follow-up， 2 cases were discontinued due to economic reasons， and the rest were divided into observation group (49 cases) and control group (51 cases).The observation group was treated with metformin combined with dapagliflozin， while the control group was treated with metformin combined with acarbose.After treatment of 12 weeks，patients were followed up and recorded fasting blood glucose， postprandial blood glucose， glycosylated hemoglobin（HbA1c）， body weight， body mass index， blood pressure， urinary glucose， urinary protein， HOMA-IR， blood glucose compliance time， the incidence of hypoglycemia， urogenital tract infection， ketoacidosis， gastrointestinal tract reaction， rash and other adverse reactions. Results： After treatment， there were statistically significant differences in diastolic blood pressure， HbA1c， fasting blood glucose， postprandial blood glucose， body weight， body mass index， urine glucose， urine protein， HOMA-IR， and blood glucose reaching standard time in the two groups compared with that before treatment. These indexes of the observation group were better than that of the control group(P<0.05).No hypoglycemia， ketoacidosis or gastrointestinal reactions occurred in the observation group.The most common adverse reactions were urogenital tract infection (8.2%) and occasional rash (2%). Conclusion： The efficacy of dapagliflozin combined with metformin in the treatment of type 2 diabetes is better than that of metformin combined with acarbose in the treatment of type 2 diabetes， which can control blood glucose steadily and reduce weight， and has good safety. mass index, blood pressure, urinary sugar, urinary protein, blood glucose compliance time, hypoglycemia, urogenital tract infection, ketoacidosis, gastrointestinal tract reaction, rash and other adverse reactions.Results: Compared with the control group after treatment, there were statistically significant differences in diastolic blood pressure, HbA1c, fasting blood glucose, postprandial blood glucose, body weight, body mass index, urine glucose, urine protein, homa-ir, and blood glucose reaching standard time between the observation group and the control group (P < 0.05).No hypoglycemia, ketoacidosis or gastrointestinal reactions occurred in the observation group.The most common adverse reactions were urogenital tract infection (8.2%) and occasional rash (2%).Conclusion: The efficacy of dapagliflozin combined with metformin in the treatment of type 2 diabetes is better than that of metformin combined with acarbose in the treatment of type 2 diabetes, which can control blood glucose steadily and reduce weight, and has a good safety.