Type 2 diabetes is the most common type of diabetes. Diabetes mellitus is a chronic metabolic disease characterized by hyperglycemia caused by a variety of reasons. It can be categorized into type 1 diabetes, type 2 diabetes, gestational diabetes, and special types of diabetes. Type 2 diabetes is prevalent in middle-aged and elderly people and is caused by a combination of genetic and environmental factors. The underlying cause is a relative lack of insulin and/or insulin resistance. Typical symptoms are three more and one less, i.e., eating more, drinking more, urinating more and losing weight. Among the environmental factors, the risk factors that induce type 2 diabetes include obesity or overweight, sedentary lifestyle, high sugar and high oil diet, high blood pressure, high blood lipids, excessive mental stress and other factors. Therefore, in order to better prevent the occurrence of type 2 diabetes mellitus, it is necessary to reasonably control body weight, adhere to moderate exercise, and pay attention to reasonable diet. Patients with type 2 diabetes should be actively treated and control their blood glucose level under the guidance of doctors, which can prevent and delay the occurrence of complications and improve the quality of life.