Abstract: Objective To explore the efficacy and safety of dapagliflozin in patients with type 2 diabetes mellitus(T2 DM) with poor glycemic control. Methods Ninety-six T2 DM patients who had poor glycemic control were enrolled in our hospital from January 2017 to December 2018, and divided into observation group and control group by simple random, 48 cases in each. The control group was treated with metformin combined with acarbose, and the observation group treated with dapagliflozin on the basis of control group. The FBG, 2 hPBG, and HbA1 c at different points were tested by variance. The body weight, waist circumference, TC, TG, LDL-C, HDL-C, SBP and DBP, and the daily dose of insulin were tested by t test, while HbA1 c compliance rate, composite endpoint compliance rate, incidence of adverse reactions were tested by χ² tests. Results Overall comparison: the interaction between FBG, 2 hPBG, HbA1 c, time point, grouping and time was statistically significant(F=79.576, 85.433, 43.369, all P<0.05). When the grouping factor is fixed, the comparison of FBG, 2 hPBG and HbA1 c at different time points is statistically significant(F=127.830, 151.870, 97.566, all P<0.05); when the time factor is fixed, the comparison of FBG, 2 hPBG and HbA1 c between groups It has statistical significance(F=45.652, 61.546, 21.006, all P<0.05). Compared with before treatment, the FBG, 2 hPBG and HbA1 c of the two groups at 4 weeks, 8 weeks and 16 weeks of treatment were significantly reduced(all P<0.05). The compliance rates of HbA1 c in the observation group and the control group were 60.42% and 56.25%, and the difference was not statistically significant(χ²=0.171, P>0.05). The composite endpoint compliance rate in the observation group was 45.83%, which was higher than the control group by 25.00%(χ²=4.554, P<0.05). The incidence of hypoglycemia in the observation group was 4.17%, which was lower than the control group by 18.75%(χ²=5.031, P<0.05). Conclusion Dapagliflozin is ideal for treating hypoglycemic T2 DM patients with hypoglycemic effect, can reduce the amount of insulin, and has high safety.