Whether diabetic patients can drink black coffee should be decided according to the individual’s physical condition. Black coffee contains low calories and sugar, if the diabetic patient’s condition is relatively stable, you can drink some black coffee without sugar in moderation, when you drink black coffee, try not to choose to drink at night, because black coffee will stimulate dopamine, which is easy to make the patient appear insomnia phenomenon. If the diabetic patient’s condition is still unstable, it is not recommended to drink black coffee, because black coffee contains caffeine, to avoid stimulation of the gastrointestinal mucosa, affecting the gastrointestinal absorption of drugs, which is not conducive to the control of the condition. Moreover, black coffee will make diabetic patients in a state of excitement, if the disease in the attack period drink black coffee, will affect the patient’s sleep quality, which will not be conducive to the control of the patient’s body blood sugar. Patients should decide whether to drink black coffee, pay attention to the control of blood glucose, take hypoglycemic drugs in time to control, and eat less sugar-rich food.