Animal insulin: Animal insulin is a heterogeneous protein for human, which has strong immunogenicity and is prone to allergic reactions and fat atrophy at the injection site, and long-term application may produce antibodies, resulting in reduced therapeutic efficacy. Human insulin: Compared with animal insulin, its main advantages include significantly lower immunogenicity, higher biological activity, faster absorption rate and lower incidence of fat atrophy at the injection site. Short-acting insulin: It is the common insulin we use. Intermediate-acting insulin: neutral ichthyoprotein zinc insulin (NPH), which is a white suspension liquid, and this insulin can only be used for subcutaneous injection. Long-acting insulin: i.e. ichthyosemin zinc insulin (PZI), which is also a white suspension, and like neutral insulin, it can only be used for subcutaneous injection and not for intravenous injection. Premixed insulin: It is a premixed preparation made of short-acting insulin and intermediate-acting insulin in a certain ratio. It can control blood sugar more effectively, treat more conveniently, more flexibly, less nocturnal hypoglycemia, better simulate human physiological insulin secretion, and can provide physiological insulin therapy for patients. Human insulin analogues: Using recombinant DNA technology, human insulin analogues have small structural differences from human insulin, low immunogenicity, and can mimic the physiological effects of normal insulin. However, the price is higher. Ultra-short-acting insulin: Compared with short-acting insulin, it has a faster onset of action, can be injected immediately before a meal, has an earlier peak time, has a shorter duration, is less likely to have hypoglycemia before the next meal, has a better glucose-lowering effect, is more convenient to use, and has better patient compliance. Long-acting human insulin analogues: stable absorption, constant release into blood, long duration of action, good repeatability, can effectively control fasting blood glucose, and less likely to cause blood glucose fluctuations and nighttime hypoglycemia, which is a more ideal form of basal insulin. Premixed human insulin analogues: (Duplex human insulin analogues) Rapid-acting insulin provides faster and higher peak of insulin secretion at mealtime, and the synchronization with postprandial blood glucose peak is greatly improved, which effectively reduces the drift of postprandial blood glucose. Fast-acting insulin can effectively lower post-prandial blood glucose while the blood concentration drops rapidly, reducing pre-meal hypoglycemia, and the clear protein-bound insulin component provides basal insulin supplementation, effectively lowering fasting blood glucose. The pre-meal injection improves the flexibility of mealtime and the compliance of treatment for patients. Combined with these features, premixed insulin analogs are not only effective in controlling postprandial and fasting glucose, but also simple and convenient in application, and are often used for initial insulin therapy. Inhaled insulin is a new insulin dosage form, but inhaled insulin preparations, like other inhaled preparations, can lead to atrophy of the nasal mucosa with long-term inhalation. In conclusion, various insulin types are abundant nowadays, and different insulin types and treatment plans should be selected according to the different conditions of patients. As far as our country is concerned, human insulin is the main type of insulin currently used in China.