Emotional fluctuations, unbalanced diet, strenuous exercise, and irrational use of hypoglycemic medication may all lead to large fluctuations in blood glucose levels. Excessive fluctuation of blood glucose can be seen in diabetic patients who eat an unbalanced diet, eat a lot of sweets or foods with a high glycemic index, resulting in a sharp rise in blood glucose. Diabetic patients use glucose-lowering drugs irrationally, do not follow the doctor’s instructions to take a reasonable dose of glucose-lowering drugs, resulting in blood sugar fluctuations. Diabetic patients should pay attention to regulating emotions, do not recommend overeating, do not recommend eating a lot of food with high glycemic index, do not recommend fasting exercise. If blood glucose fluctuates too much, it is necessary to change the glucose-lowering drug treatment plan or use insulin to lower blood glucose under the guidance of doctor’s interview. Pay attention to monitoring blood glucose in daily life to prevent blood glucose from being too low or too high.