Insulin release assay refers to let the patient fasting, quantitative oral glucose to make blood glucose rise, stimulate the β-cells of the pancreatic islets, release insulin, through the measurement of fasting, half an hour after meal, one hour, two hours, three hours of plasma insulin level to understand the reserve capacity of β-cells, but also helps to help diabetes mellitus typing and guide the treatment. Clinical insulin release assay curves can be categorized into three types, broadly speaking, insufficient insulin secretion type, increased insulin secretion type and impaired insulin release type. Depending on the patient’s curve, different treatment options are selected.