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 rich in nutrition will provide more nutrients for the growth of lung cancer, and some even starve the patient to death, which are not based on science. On the contrary, many facts show that poor nutrition is extremely detrimental to the treatment and recovery of patients, such as slow recovery after surgery, poor tolerance to radiotherapy and chemotherapy, and low immune function, resulting in infection and even deterioration. Therefore, lung cancer patients must pay attention to food nutrition. The consumption and poor appetite of lung cancer patients due to lung cancer 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 and before and after treatment. If the weight loss indicates “not enough”, it is necessary to increase the amount of diet. Patients with lung cancer consume a lot, so they need 20% more protein and calories than normal people. If malnutrition has already occurred, more protein can be added. The best protein intake is vegetable protein and some animal protein. In addition, attention should be paid to choosing low-fat, low-salt and vitamin- and mineral-rich foods, which are beneficial to the treatment and recovery of lung cancer patients. In arranging the diet of lung cancer patients, besides considering the above nutritional factors, attention should also be paid to making full use of the anti-cancer factors in food. Some foods can induce cancer while others can fight cancer. Lung cancer patients should try to avoid cancer-inducing foods and eat more cancer-fighting foods. According to research, common anti-cancer foods include cruciferous vegetables (such as cabbage and cauliflower, etc.), radish, garlic, sour plum, soybean, beef, etc. The diet of lung cancer 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 appetite of patients, so a pleasant eating environment should be created for patients. The diet of lung cancer patients includes common rice, soft rice, semi-liquid food and liquid food, which should be provided according to the patient’s specific condition and digestion and absorption ability. For example, some patients after neck surgery are prone to choking and coughing when they eat, so they dare not eat, so they should be given soft rice or soft and dry semi-liquid food. Patients with neck radiation therapy have less saliva, dry and painful throat and difficulty in swallowing, so diet should be more watery and cooler. As lung cancer patients receive different treatments, they should also be given appropriate diet according to the specific treatment methods. For example, patients receiving radiotherapy and chemotherapy often have abnormal taste and anorexia, and everything they eat becomes bitter or tastes wrong. The ways to deal with this are: to eat more high-protein and high-nutrition foods and new chub-chamomile vegetables, etc.; to add condiments to food; to make more food with good color, flavor and shape to arouse appetite; to drink a small cup of acidic beverage before meal.