Many type 1 diabetes mellitus require insulin therapy, and puberty is a clear sign of the appearance of secondary sexual characteristics. After puberty, the secretion of sex hormones, growth hormone and other insulin-antagonist hormones increases, blood glucose level rises significantly and fluctuates greatly compared with that before puberty, and the condition is very unstable, which increases the need for insulin. In order to adapt to this change during puberty, it is necessary to strengthen the monitoring of blood glucose, and adjust the insulin treatment program according to the monitoring results in order to help the patient to pass through puberty smoothly. Failure to pay attention to insulin regulation can lead to excessive changes in blood glucose or the development of acute complications, which in the long term can lead to chronic complications. Clinically, adolescence (i.e., early morning hyperglycemia) is more pronounced, and particular attention should be paid to morning glucose monitoring. If necessary, dynamic glucose monitoring can be considered, and insulin dosage can be adjusted according to the changes in blood glucose, and if necessary, insulin pump therapy, especially closed-loop insulin pumps, can be used. After puberty, insulin dosage will be reduced and the condition will gradually stabilize. So the insulin regulation of type 1 diabetes during puberty is also a very important issue.