Rapid-acting insulin includes insulin lysine, insulin menthol, insulin glargine and so on. Rapid-acting insulin is characterized by short onset of action, faster peak time and shorter duration of action, which can effectively control postprandial blood glucose, and can also be used in intravenous route to rescue diabetic ketoacidosis and other diseases. It should be noted that because of the rapid onset of action of rapid-acting insulin, it is necessary to eat in time after the injection, otherwise it may cause hypoglycemia. Because of the shorter duration of action of rapid-acting insulin, the risk of nocturnal hypoglycemia is lower. The dosage of rapid-acting insulin varies from person to person and should be decided by the doctor according to the patient’s condition. Patients who need to use rapid-acting insulin treatment should be under the supervision of a doctor.