Glucose tolerance generally refers to the oral glucose tolerance test, adding 150ML of water and then drinking it only once. Oral glucose tolerance test is a glucose loading test to understand the body’s ability to regulate blood glucose and pancreatic β-cell function. Oral glucose tolerance test requires 8~10 hours of fasting after dinner on the previous day to collect blood in the morning of the next day, and then 75g of glucose is added to about 300 mL of water (1.75g per kilogram of body weight for children), and it is required to be taken at once, that is to say, it is enough to drink it only once, and then blood is collected to observe blood glucose concentration on an empty stomach, in half an hour, in an hour, in two hours, and in three hours, respectively. Patients who need to do oral glucose tolerance test should be under the guidance of a doctor.