Blood glucose 1.5 hours after meal is considered as random blood glucose, which should be less than 11.1 mmol/L. Diabetic patients usually monitor blood glucose 2 hours after meal. Diagnostic criteria for diabetes mellitus: diabetes mellitus can be diagnosed by fasting blood glucose ≥7.0 mmol/L, or 2-hour post glycemic load blood glucose ≥11.1 mmol/L, or random blood glucose ≥11.1 mmol/L, accompanied by three more and one less symptom (drinking, eating, urinating, and weight loss). Blood glucose at 1.5 hours after meal is considered as random blood glucose, which should be less than 11.1 mmol/L in normal people, and if blood glucose at 1.5 hours after meal is greater than 11.1 mmol/L, the possibility of diabetes mellitus should be considered. In case of diabetes, 2-hour postprandial blood glucose should be monitored, and it is recommended that 2-hour postprandial blood glucose should be no more than 10.0 mmol/L. Elevated postprandial blood glucose, it is recommended to seek timely medical treatment under the guidance of a doctor.