Glucose tolerance test is a common clinical method to check diabetes, which can clarify whether patients have abnormal glucose tolerance and thus confirm the diagnosis of diabetes, and can be completed in 3 steps. 1.Fast stomach 8-12 hours before the test, go to the endocrinology department of the hospital for blood sampling, and need to take 1 tube of about 3ml of blood intravenously, at this time for fasting blood sugar; 2.Sugar powder of 75g of glucose provided by the hospital, dissolved in 300ml of warm water, drink it within 5 minutes, start timing from the time of entrance, and take the second intravenous blood 60 minutes after the entrance; 3. The third intravenous blood is taken 120 minutes after taking the first sugar water. If the ward patients in order to further clarify the condition, 5 steps are required. The same as the outpatients is the first venous blood collection on an 8-12 hour fast, and the difference with the outpatients is the subsequent increase of two blood collection times, i.e. the second blood collection 30 minutes after drinking the first sip of sugar water, the third blood collection 60 minutes, the fourth blood collection 120 minutes, and the fifth blood collection 180 minutes. The glucose tolerance test can clarify whether the patient’s blood glucose is normal or not, and the diagnosis of diabetes can be clarified when the blood glucose is ≥11.1 mmol/L 2 hours after meal. When a pregnant woman has a glucose tolerance test and one of the three blood glucose tests is higher than the normal blood glucose value, the diagnosis of gestational diabetes can be satisfied.