The so-called homology of medicine and food generally contains two meanings. First, food itself can be a part of medicine. For example, the earliest Chinese medicine book "Shennong Materia Medica" to "Compendium of Materia Medica" in the Qing Dynasty included food in medical books, and there were also dietotherapy and medicated diets in Chinese medicine books. However, food and medicine are different after all. Although food has a certain therapeutic effect, its therapeutic effect is limited and can only play an auxiliary role. Drugs can cure diseases, but they can't be used for a long time, and food can be eaten often. In addition, drugs will always have adverse reactions, but food is different. On the other hand, both Chinese medicine and food can be used in TCM theory. Like Chinese medicine, food has four flavors and five flavors, and can also be eaten according to the difference of cold, heat and cold. As we all know, pears can relieve cough. Patients who often catch a cold and cough can buy pears for themselves, or stew pear crystal sugar, which can relieve cough and resolve phlegm. In fact, this method is only useful for wind-heat colds; A cold caused by a cold will not be effective if eaten, and sometimes it will delay the time for catching a cold and coughing. Therefore, we should use dietotherapy and medicated diet, and we should also understand some Chinese medicine theories and some Chinese medicine properties theories. The homology of medicine and food also comes from this theory of traditional Chinese medicine.