Objective To investigate the clinical effect of metformin combined with insulin aspartate in the treatment of diabetes.Methods A total of 80 patients with diabetes admitted to the internal medicine department of Shanxian County People's Hospital from June 2022 to June 2023 were selected as the study objects and divided into control group(n=40,insulin aspartate treatment alone)and study group(n=40,insulin aspartate combined with metformin)by random number table method.The effective rate,blood glucose level,blood glucose control,islet function and inci-dence of adverse reactions were compared between the two groups.Results The treatment effective rate of the study group was higher than that of the control group,and all blood glucose levels of the study group were lower than those of the control group,and the blood glucose control and islet function of the study group were better than those of the control group,and the differences were statistically significant(all P<0.05).There was no significant difference in the incidence of adverse reactions between the two groups(P>0.05).Conclusion The combination of metformin and insu-lin aspartate in the treatment of diabetes can effectively control the blood sugar level,improve the islet function,re-duce the dosage of insulin,and do not increase adverse reactions,with high safety and accurate efficacy.