Insulin can be divided into three categories according to the source: 1. animal insulin: at present, the subcutaneous application has been less, basically for intravenous use, like acute complications of ketoacidosis, hypertonic coma patients or diabetic patients with glucose; 2. human insulin: it is a type of insulin synthesized through genetic engineering with 51 safe gene sequences identical to human, currently more clinical use, human insulin There are three main categories: medium-acting, premixed and short-acting, and each manufacturer has a different drug name and trade name. Insulin is generally used more subcutaneously, premixed twice a day injection, short-acting can be used with medium-acting insulin before bed, three short and one long program; 3, insulin analogues: after restructuring, through recombinant genetic engineering to slightly change the amino acid sequence of the drug, there are fast-acting insulin analogues, premixed insulin analogues, and long-acting insulin analogues. The fast-acting insulin analogues are menthol insulin, lysergic insulin and glulis insulin, which are fast in and fast out, so that you can eat soon after insulin injection without waiting. Pre-mixed in different ratios, like menthol insulin 50 and lysergic insulin 50, which are 50% short-acting as well as 50% medium-acting premixed, are more suitable for patients whose postprandial blood glucose elevation is the main cause, and premixed analogues can be injected 2-3 times a day. There are also 25% and 75% ratios, such as lysergic insulin 25 is eugenol 25, which is more suitable for patients with mainly elevated fasting blood glucose, long-acting insulin analogues are currently in clinical use, such as glargine insulin, detergent insulin and degludec insulin.