Different types of insulins have different duration of action. According to the source and chemical structure, insulins can be divided into animal insulins, human insulins and insulin analogues. According to the onset of action and maintenance time, insulins can be divided into short-acting, medium-acting, long-acting and premixed insulins, and insulin analogs can be divided into fast-acting, long-acting and premixed insulin analogs. Short-acting insulin can last 3-5 hours, medium-acting insulin can last 8-12 hours, and long-acting insulin can last 20-28 hours, and premixed insulin generally needs to be injected twice a day because it contains different ingredients.