Diabetes is known as the “cancer that never dies”, which shows how dangerous it is to health and how difficult it is to treat. Most people with diabetes require lifelong medication, and insulin injections are the most effective form of treatment. However, it is important to understand that there are many different types of insulin and the dosage varies greatly. Patients with diabetes need to follow their doctor’s prescription for which insulin to use and how to use it. Although the effect of insulin injection to control blood sugar is better, but after the injection still need to pay attention to the following matters, otherwise the consequences are also very serious. First, the time of injection, the time of insulin injection and diet is closely related to the time, for example, short-acting Novolin R needs to be injected 30 minutes before meals, premixed NovoRel 30 can be injected immediately before meals. Patients control the injection time, can effectively play the role of drugs, but also to avoid the occurrence of hypoglycemia. Second, insulin and glucagon-like peptide 1 (GLP-1) receptor agonist must be injected into healthy subcutaneous adipose tissue, avoiding injection into intradermal, muscular, scar and fatty hyperplasia tissue. The injection sites for insulin include the upper outer arm, abdomen, anterolateral thigh and upper 1/4 of the buttocks, where the subcutaneous adipose tissue is conducive to the absorption of insulin and the nerve endings are less distributed, and the uncomfortable feeling of injection is relatively less. IV. All adults, regardless of age, gender and body mass index (BMI), are recommended to use 4 mm insulin pen needles with a 90° vertical approach. With pen needles or syringes >4 mm in length (where the distance from the skin surface to the muscle fascia at the injection site is less than the length of the needle), proper skin pinching techniques or angled needle insertion must be used to avoid intramuscular injection. Fifth, pay attention to the preservation of drugs, insulin is a protein, which needs to be stored in the refrigerator refrigerated layer again, and should not be stored for a long time. Insulin in use should be kept at room temperature, choose a cool and dry place to place, and avoid direct sunlight. Before injection, insulin should be taken out and brought to room temperature. If it is injected just after it is taken out of the refrigerator, the injection site may be stimulated by the low temperature. Observe the injection site for hard knots, skin damage and inflammatory exudation, and if necessary, ask professional medical personnel for treatment.