Objective To investigate the clinical effect of intravenous insulin infusion in children with diabetes melli-tus whose first symptom was ketoacidosis.Methods A total of eighty children with the first symptom of ketoacidosis admitted to Longyan People's Hospital from January 2019 to January 2024 were selected as the study objects,and they were divided into the conventional group(n=40,Novalurin R+Novalurin N)and the study group(n=40,Noval-urin R+Dieter's insulin)according to random order table method.The treatment effect,blood glucose levels(fasting blood glucose,2-hour postprandial blood glucose)and complications were compared between the two groups.Results The hospitalization time,urinary ketone body elimination time and blood pH recovery time in the study group were sig-nificantly lower than those in the conventional group,and the differences were statistically significant(all P<0.05).Af-ter treatment,fasting blood glucose and 2-hour postprandial blood glucose levels in two groups were decreased com-pared with those before treatment,and those in the study group were lower than the conventional group,and the differ-ences were statistically significant(both P<0.05).The total incidence of complications in the study group(2.50%)was lower than that in the conventional group(20.00%),and the difference was statistically significant(χ2=4.507,P<0.05).Conclusion The application of Novolin R combined with Dieter's insulin to pediatric diabetic children whose first symptom is ketoacidosis has a better clinical therapeutic effect and reduces the children's blood glucose level and the incidence of complications.