Tumor is a consumptive disease, and patients inherently suffer from malnutrition. In the treatment of tumor, patients will suffer from different degrees of loss of appetite and reduction of food intake, resulting in the deterioration of nutritional status, which affects the therapeutic effect and quality of life. Nutritional therapy can correct or improve the nutritional status of patients, improve the immune function and anti-disease and anti-cancer ability of the body, and achieve the purpose of “supporting the righteous and eliminating the evil”. It can also improve patients’ tolerance to surgery, radiotherapy and chemotherapy, reduce postoperative infection and accelerate wound healing. The daily diet of cancer patients should follow 3 principles – nutrition, diversity and balance. Specific operation. 1. The following 4 points should be kept in mind: (1) Maintain normal weight and no malnutrition occurs. (2) Avoid the intake of carcinogens: eat less fried, smoked and barbecued food, no pickled food, no moldy food, burnt meat, long-stored rotten vegetables, etc.; also quit smoking. (3) Increase the intake of protective foods: such as dietary fiber, foods rich in antioxidants, and foods that can improve immune function. (4) Adjust the subhealth state through dietary therapy and medicinal food. (1) It is advisable to eat more foods with immune enhancing and anti-lung cancer effects, such as barley, sweet almond, ling, oyster, jellyfish, yellowtail, crab, sea cucumber, poria, yam, jujube, string bean, shiitake mushroom, walnut and turtle. (2) It is advisable to eat white fruit, radish, mustard, almond, orange peel, loquat, olive, jellyfish, water chestnut, kelp, nori, winter melon, loofah, sesame, figs, pine nuts, walnuts, rooibos, peach, orange and pomelo. (3) It is advisable to eat cucumber, winter melon, bitter melon, lettuce, eggplant, lily, amaranth, capers, horsetail, watermelon, pineapple, pear, persimmon, orange, lemon, olive, mulberry seeds, water chestnut, duck and green fish. (4) It is advisable to eat plum, lotus root, sugar cane, pear, cotton, jellyfish, sea cucumber, lotus seed, diamond, kelp,, black bean, tofu, caper, eggplant, milk, carp, squid, yellowtail, snapper, oyster. (5) It is advisable to eat rape, loofah, kiwi, walnut, buckwheat, poppy, almond, eggplant, peach, mustard, quail, kumquat, crab, orange, wheat and carp for chest pain. (6) It is advisable to eat foods to reduce the side effects of radiotherapy and chemotherapy: goose blood, mushrooms, cinnamon, eels, walnuts, snapper, kiwi, Ulva, golden needle, dates, sunflower seeds, apples, carp, mung beans, soybeans, red beans, shrimp, crab, silver beans, loach, mahi-mahi, green tea. (7) It is advisable to eat fungus, tomatoes, carrots, mushrooms, peanuts, lilies, jellyfish, almonds, lotus seeds, pears, water chestnuts, bananas, milk, soybeans, and animal liver. Avoid] (1) Avoid smoking and alcohol. (2) Avoid spicy stimulating food: onion, garlic, leek, ginger, pepper, chili, cinnamon, etc. (3) Avoid frying, barbecue and other hot food. (4) Avoid greasy, sticky and phlegm-producing food.