To investigate the effects of Sini Decoction combined with metformin on glucose metabolism and lipid metabolism in patients with type 2 diabetes mellitus(T2DM).Methods:A total of 112 T2DM patients who were admitted to the Department of Endocrinology of Hefei First People's Hospital from January 2019 to December 2021 were selected and divided into a control group(54 cases) and an experimental group(59 cases) according to the random number table.The control group was given metformin hydrochloride tablets,while the experimental group was given modified Sini decoction on this basis.The clinical efficacy,fasting blood glucose(FBG),2 h postprandial blood glucose(2 h PBG),glycosylated hemoglobin(HbA1c),total cholesterol(TC),triglyceride(TAG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),brain memory function score and adverse reactions of the two groups were compared.Results:The total effective rate in the experimental group was higher than that in the control group(P<0.05).Before treatment,there was no significant difference in the levels of FBG,2 h PBG,HbA1c,TC,TAG,LDL-C and HDL-C between the two groups(P>0.05).After treatment,the levels of FBG,2 h PBG,HbA1c,TC,TAG and LDL-C in the experimental group were lower while the level of HDL-C was higher than those in the control group(P<0.05); in addition,each brain memory function score in the experiment was superior to that in the control group(P<0.05); no marked significance was observed in adverse reactions between the two groups(P>0.05).Conclusion:Sini Decoction combined with metformin could reduce the levels of blood glucose and blood lipids in T2DM patients and improve their quality of life,with good clinical effect and few adverse reactions.