Apple is rich in sugar, acid, aromatic alcohol and pectin, and contains vitamins B and C, calcium, phosphorus, potassium, iron and other nutrients. As early as the Tang Dynasty, the medicinal use of apples was recorded. Apples not only benefit the heart and strengthen the spleen, but also promote fluid production and quench thirst. They also have the functions of "moistening the lungs and pleasing the heart, promoting fluid production and appetizing, and sobering up". Apples are sour, sweet and cold. Modern medical research has proved that patients with severe edema eat more apples, which is beneficial to supplement potassium and reduce side effects. Eating more apples during pregnancy can not only supplement vitamins and other nutrients, but also adjust the balance of water saving, salt and electrolyte to prevent acidosis caused by frequent vomiting. Apple can also be used as a whole intestine antidiarrheal agent. In Compendium of Materia Medica, there is a saying that "half-cooked apples 10 slices, 2 liters of water and fried apples 1 liter are eaten together". There are also folk methods to treat chronic diarrhea, neurocolitis and intestinal tuberculosis with apples. Germans also use "Moro Apple Therapy" to treat enteritis. In addition, eating an apple on an empty stomach every morning and evening can treat dry stool. Eating apples after meals has a certain effect on nausea and indigestion; Patients with hypertension can get antihypertensive effect by eating apples three times a day, each time 1-2 apples.