Metformin belongs to the biguanide class of hypoglycemic drugs, its mechanism of action is able to inhibit the absorption of glucose in the small intestine and reduce the synthesis of glucose in the liver, increase the uptake and utilization of glucose in peripheral tissues, and then reduce the fasting and postprandial blood glucose. Clinically, it can be used to treat patients with type 2 diabetes who cannot control their blood glucose well with exercise and diet alone. It should be noted that people who are allergic to the drug, have liver or renal insufficiency, serious infection or trauma should not take Metformin treatment; there may be nausea, vomiting, diarrhea, rash and other adverse reactions after taking the drug. Patients who need to take metformin treatment should standardize the use of medication under the guidance of a doctor, do not increase or decrease the dose by yourself, and go to the hospital as soon as possible if you feel unwell after using the drug.