Diabetes mellitus is one of the most common chronic diseases. With the improvement of people’s living standard, the aging of the population and the increase of the incidence of obesity, the incidence of diabetes is on the rise year by year. The prevalence of diabetes in China has reached 2%, and according to statistics, 40 million people have been diagnosed with diabetes in China, and the number is increasing at a rate of 1 million per year. Diabetes is a common disease caused by the interaction of genetic and environmental factors, with hyperglycemia as the main clinical hallmark and common symptoms such as excessive drinking, polyuria, polyphagia and weight loss. If diabetes is not effectively treated, it can cause damage to multiple systems in the body. It causes a series of metabolic disorders such as protein, fat, water and electrolyte syndrome, of which hyperglycemia is the main sign. Typical clinical cases may show symptoms such as polyuria, polyphagia, polyphagia and lethargy, i.e. “three more and one less”.