The auxiliary tests for diabetes include fasting blood glucose, blood glucose 2h after meal, glycosylated hemoglobin, urinalysis, lipid measurement, and the more important test is islet function analysis, which includes the measurement of fasting, 1h, 2h C-peptide, or insulin level. In addition, diabetes-related antibodies, such as antibodies to glutamic acid decarboxylase, antibodies to insulin, and antibodies to pancreatic islet cells, are also of great importance in the typing and diagnosis of diabetes. In addition to the above basic tests, liver and kidney function tests, urine microalbumin tests, and funduscopic tests will be included, which are diagnostic for assessing the chronic complications of diabetes mellitus.