Abstract： Objective： To observe the clinical effect of Qigui Tongluo tang combined with dimethylbiguanide for type 2 diabetes mellitus and its effect on blood glucose fluctuation. Methods：A total of 150 cases of patients with type 2 diabetes mellitus were selected and divided into the control group and the study group according to the random number table method， with 75 cases in each group. The control group was treated with dimethylbiguanide， and the study group was treated with Qigui Tongluo tang combined with dimethylbiguanide. After one month of treatment，the clinical effects in the two groups were compared. Before and after treatment，glycosylated hemoglobin A1c(HbA1c)，2- hour postprandial blood glucose(P2hBG)， fasting blood glucose(FBG) and mean amplitude of glycemic excursions(MAGE) in the two groups were compared. Results：The total effective rate was 92.0% in the study group and 72.0% in the control group，the difference being significant(P＜0.05). After treatment，The levels of HbA1c，FBG and P2hBG in the two groups were decreased when compared with that before treatment(P＜0.05)，and the levels of HbA1c，FBG and P2hBG in the study group were lower than those in the control group(P＜0.05).The incidence of hypoglycemia was 5.3% in the study group and 14.7% in the control group， the difference being significant(P＜0.05). Before treatment， there was no significant difference being found in the comparison of MAGE between the two groups(P＞0.05). After treatment， MAGE in the two groups was decreased when compared with that before treatment(P＜0.05)，and the MAGE in the study group was lower than that in the control group(P＜ 0.05). Conclusion： The therapy of Qigui Tongluo tang combined with dimethylbiguanide for type 2 diabetes mellitus can improve the clinical effect，the levels of HbA1c，FBG and P2hBG in serum and blood glucose fluctuation，as well as reduce the incidence of hypoglycemia.