Chemotherapy is short for chemotherapy, which is used to kill cancer cells through the use of chemotherapeutic drugs to achieve treatment. Tumor is a consumptive disease, which will cause patients’ malnutrition. Therefore, it is very important to promote appetite and strengthen nutrition for the recovery of tumor patients. In daily life, we should pay attention to reasonable nutrition, eat more high protein, multivitamin, low animal fat, easily digestible food and fresh fruits and vegetables, and do not eat spicy and stimulating food. When patients have decreased appetite, anorexia, vomiting, etc., diet should be based on strengthening the spleen and stomach. Such as hawthorn, which can effectively prevent vomiting and also promote digestion. Walnuts, barley, radish, sunflower seeds, millets, Ulva spp. and fish not only improve the patient’s appetite and reduce the digestive burden of the digestive tract, but also reduce the side effects associated with chemotherapy. If the patient has oral mucous membrane rupture, use rose hips, honeysuckle and chrysanthemum as tea substitutes. Patients with declining leukocyte and blood count reactions should supplement animal offal, such as heart and liver, bone marrow, fish, jujube, cinnamon garden, adzuki beans, pig’s feet, lean meat, quail, mushrooms, duck blood, walnuts, snapper, etc. There are foods rich in high protein, which can enhance the nutritional balance of patients while boosting their leukocyte count. Eat more natural, pure wild foods and less fine-grained processed foods. Use more steaming, boiling and stewing in cooking, and minimize fried and deep-fried foods. Rational arrangement of diet can improve immunity, not too much supplement and not too little nutrition. Vitamin A can prevent the transformation of epithelial cells and repair the damage of epithelial cells, so it can prevent various kinds of tumors; B vitamin deficiency can accelerate the formation and growth of tumors; vitamin C can block the synthesis of nitrosamines in the body and reduce the incidence of tumors. During chemotherapy and radiotherapy, eating more fresh vegetables and fruits rich in vitamins has obvious appetizing effect. Such foods can not only increase resistance, but also enhance appetite. Appropriate use of TCM diet therapy. Lingzhi porridge has therapeutic effects on cancers such as blood cancer, liver cancer and metastatic cancer; corn porridge not only can fight cancer, but also can regulate the middle and stomach, which has a comprehensive health care effect; sea cucumber soup, the polysaccharide and peptide components in sea cucumber can alleviate the toxic side effects of radiotherapy and enhance the immunity of the body, which is the preferred diet therapy for many cancer patients. Lily porridge has the effect of stopping cough, stopping bleeding and appetite, which is suitable for lung cancer; pumpkin porridge can eliminate the carcinogenic effect of nitrosamines.