Objective To study the effect of dietary control combined with insulin therapy on blood glucose level in gestational diabetes mellitus.Methods A total of 90 patients with gestational diabetes admitted to Yangzhuang Town Central Health Center of Yishui County from December 2021 to December 2023 were selected as the study objects,and were divided into observation group and control group by random number table method,with 45 cases in each group.The control group was treated with insulin alone,and the observation group was treated with diet control com-bined with insulin.The therapeutic effect of the two groups was compared.Results After treatment,the blood glucose index and glycosylated hemoglobin level in the observation group were lower than those in the control group,and the differences were statistically significant(both P<0.05).The total effective rate of treatment in the observation group was higher than that in the control group,and the incidence of adverse pregnancy outcome was lower than that in the control group,and the differences were statistically significant(both P<0.05).Conclusion The implementation of di-etary control combined with insulin therapy can effectively improve the quality of clinical management of patients with gestational diabetes mellitus,improve the control effect of patients'blood glucose level,reduce the occurrence of ad-verse pregnancy outcomes,and improve the pregnancy safety of patients.