Objective To study the effect and potential adverse reactions of acarbose combined with metformin hydro-chloride in the treatment of type 2 diabetes mellitus.Methods The clinical data of 125 patients with type 2 diabetes mellitus admitted to Shanxian Haijiya Hospital from January 2023 to January 2024 were retrospectively selected.Ac-cording to different treatment methods,they were divided into single group(62 cases,treated with acarbose)and com-bined group(63 cases,treated with acarbose combined with metformin).The levels of glucose and lipid metabolism in-dexes,the total incidence of adverse reactions and clinical efficacy were compared between the two groups.Results After treatment,the levels of fasting plasma glucose,2-hour postprandial plasma glucose,glycated hemoglobin A1c,total cholesterol,triglyceride,low density lipoprotein cholesterol in the combined group were lower than those in the single group,and the differences were statistically significant(all P<0.05).The total effective rate of the combined group was higher than that of the single group,and the difference was statistically significant(P<0.05).There was no significant difference in the total incidence of adverse reactions between the two groups(P>0.05).Conclusion Acar-bose combined with metformin hydrochloride in the treatment of type 2 diabetes mellitus can control the glucose and lipid levels more effectively than metformin alone,improve the treatment efficiency,and will not significantly increase the incidence of complications.