At present, there are three types of insulin in the market.1 The first type of insulin is a kind of insulin in a bottle, common insulin, which is more commonly used in clinical practice. This kind of insulin contains 400 units of insulin in 10ml and 40 units of insulin in 1ml, which can be extracted with a 1ml syringe and injected subcutaneously, or put into a liquid drip to achieve the purpose of hypoglycemia treatment. 2. The third is the new insulin U300, different from the previous insulin U100, the concentration of U300 is 3ml containing 450U insulin.