Food is the material basis for cancer patients’ recovery. Paying attention to cancer patients’ diet and providing reasonable and adequate nutrition can enhance the body’s resistance, improve patients’ tolerance to treatment, ensure the successful completion of treatment plan and promote recovery. Because many people lack scientific knowledge of nutrition, there are often some incorrect ideas and practices in cancer nutrition. For example, they worry that eating more or being more nutritious will provide more nutrients for the growth of tumor, and some even starve the patient, trying to “starve” the tumor cells, which are not based on science. On the contrary, many facts show that malnutrition is extremely detrimental to patient’s treatment and recovery, such as slow recovery after surgery, poor tolerance to radiotherapy and chemotherapy, and low immune function, causing infection and even deterioration. Therefore, we must pay attention to food nutrition for tumor patients. Tumor and its various treatments can lead to malnutrition, so adequate nutrition should be given as early as possible. To arrange the diet of tumor patients, we should firstly evaluate their nutritional status, and secondly, we should determine the quality and quantity of nutrients, the form of diet and the way of supply according to the patient’s disease stage and the different treatment measures. A simple way to evaluate the nutritional status of a patient is to use weight as an indicator. Generally, healthy people usually consume enough protein and calories, so their body weight can remain stable. However, the consumption of tumor and poor appetite of tumor patients cause the objective indicator of whether the need and calorie intake are sufficient. Weight standard can be determined by age, gender and height. A more common convenient method is to compare oneself before and after the disease, before and after the treatment. If the weight loss indicates “not enough”, it is necessary to increase the amount of diet. Oncology patients consume a lot, so they need 20% more protein and calories than normal people. If malnutrition has developed, more protein can be added. The best protein intake is vegetable protein and some animal protein (milk, egg, fish, shrimp, sea cucumber, beef and mutton). In addition, attention should be paid to choosing low-fat, low-salt and vitamin and mineral-rich foods (seeds and kernels of plants such as sunflower seeds, almonds, etc.), which are beneficial to the treatment and recovery of tumor patients. To arrange the diet of tumor patients, besides considering the above nutritional factors, attention should also be paid to make full use of the anti-cancer factors in food. Certain foods can induce cancer, while others can fight cancer. Tumor patients should try to avoid cancer-inducing foods and eat more anti-cancer foods. According to research, common anti-cancer foods include cabbage, cauliflower, radish, garlic, sour plum, soybean, asparagus, bitter melon, kelp, sweet potato, pumpkin, wheat bran, tomato and mushroom. The diet of tumor patients should not only focus on its content, but also consider their hobbies and eating environment. Eating their favorite food can increase the secretion of gastric juice, which can promote appetite and improve the absorption and utilization of food. In addition, the eating environment can also affect the patient’s appetite, and a pleasant eating environment should be created for the patient. The common methods of supplementation in home care are oral, nasal feeding, and fistula tube feeding. Only when the patient has no appetite or cannot eat from the mouth is nasal feeding or fistula feeding used. 1.General diet: For cancer patients without digestive system dysfunction, general diet can be used. The ordinary diet for cancer patients should be nutritious, light and delicious, easy to digest food, containing more animal protein and vitamins, less fried food and not greasy. Ordinary diet is suitable for: (1) cancer patients recovering from surgery; (2) patients before and after chemotherapy and radiotherapy; (3) patients with non-digestive tract tumors or various cancers without digestive system dysfunction; (4) patients with fever and recovering from treatment. The general diet should pay attention to the cooking method and reasonable combination of food, so that the food is fancy, nutritious and easy to digest, and pay attention to the taste and reaction of patients, and the color and aroma should be complete. Example of diet: The general diet is similar to the healthy diet, and fried and indigestible foods are not suitable. It is necessary to supplement protein, calories and multivitamins, and animal protein-rich foods should be increased, such as more beef, chicken, fish, egg whites, milk, etc., and more fresh fruits and vegetables. 2.Soft diet: It is between ordinary diet and semi-liquid diet, with less residue, easy to chew and easy to digest. All food should be chopped, stewed and cooked softly when cooking, but it should not be cooked by deep-frying and oil frying. Soft diet is suitable for: 1) patients with weak digestive function after radiotherapy and chemotherapy; 2) patients recovering from gastrointestinal tumor surgery. Examples of soft diet: bread, dumplings, buns, liver puree, cakes, etc. Long-term consumption of soft rice, chopped vegetables, timely supplementation of vitamin c, such as fresh juice, tomato juice, etc. Vegetables with much coarse fiber, such as celery, leek, etc. should not be consumed. 3, semi-liquid food: generally liquid-based, containing very little food residue, easier to digest than soft food, easy to chew, contains less fiber, high nutritional value. As semi-liquid food contains more water and lower nutrient supply, in order to meet the nutrient and caloric energy needs of cancer, most of them are eaten in the way of few meals, 5 to 8 times a day. Semi-liquid diet is suitable for: patients recovering from tumor surgery, patients with more serious digestive dysfunction. Patients with difficulty in swallowing after oral and pharyngeal tumor surgery. Examples of meals: Rice porridge, noodles, cookies, lotus root powder, bread, wontons, etc. can be used. Only a small amount of lean meat, lamb and beef with little tendon should be used, and should be chopped and cooked, or pig liver puree can be added to the main diet and fed together. You can also eat a variety of dairy products, soy milk, tofu brain, etc. 4, liquid food: food into liquid form, no food residue, very easy to digest. You have to eat less and more meals every day, once in 2 to 3 hours, which still can’t meet the daily calories, so it can’t be consumed for a long time in general. Liquid food is suitable for: patients who have had esophageal obstruction in the middle and late stages, patients with pharyngeal and oral tumors and swallowing difficulties, patients after photodynamic surgery for pharyngeal tumors, patients with extreme physical exhaustion, and the initial intake of food after various thoracic and abdominal tumors. Examples of meals: rice soup, milk, soy milk, egg custard, fresh fruit juice, vegetable juice, etc. Juice and vegetable juice should be drenched. Patients with postoperative thoracic and abdominal tumors should avoid flatulent food, such as milk and sweet food. 5.Elemental diet: a kind of liquid nutrient with complete nutrition and composed of small molecules without dregs. Its main components are amino acids, monosaccharides, fatty acids, multiple vitamins (water-soluble and fat-soluble), minerals and trace elements and so on. The vast majority of the essential diet is digested and absorbed up to 100%. It can be placed directly into the jejunum through silicone tubes via the nose and stomach. Since the nutrient solution is semi-digested, the body only needs 65-100 cm of small intestine to be absorbed and used, which is a safe and economical nutrition support therapy. 6.There is another method of supplemental nutrition, namely total gastrointestinal nutrition, which is also known as intravenous hyper-nutrition, which is the application of sufficient calories and amino acids from intravenous input. It is generally applied to patients who cannot take in suitable nutrition for more than two weeks, especially those who are highly depleted due to diseases or injuries. The most commonly used clinical indications are as follows: ① intestinal fistula; ② after extensive resection of small intestine; ③ chronic long-term small intestinal obstruction; ④ chemotherapy stage of tumor patients; ⑤ malnutrition and hypoproteinemia. Because of the high concentration of intravenous hypernutrition fluid, it needs to be administered via a fast-flowing vein. Generally, the subclavian vein is used because this vein is in a more fixed position. When applying intravenous hyper-nutrition, attention should be paid to the preparation of nutrition solution, intubation technique, and infusion speed.