Radiotherapy can consume a lot of physical strength, energy and nutrients. Therefore, attention should be paid to nutritional supplementation during radiotherapy to ensure sufficient protein and energy. It is not necessary to restrict the diet too much, but to supply nutritious food with small amount and many meals. Radiotherapy can cause congestion and edema of esophageal mucosa and difficulty in swallowing, so according to the patient’s swallowing condition, thick liquid with light and less oil should be used, such as milk with egg, lotus root powder with egg, batter with egg, crumbled noodles, etc., or fed with tube. In short, the food is processed and cooked to be extremely soft, easy to swallow, and easy to digest and absorb, and attention should be paid to the supplementation of vitamins, minerals and trace elements. If necessary, elemental meals or nutritional preparations of large molecules of whole proteins can be taken. The effect of radiation damage on nutritional metabolism involves energy, sugar, lipids, protein, vitamins, minerals and trace elements, and the degree of effect is related to the severity of radiation damage, and attention should be paid to supplementation. When using chemotherapy or radiotherapy, upper digestive system symptoms are often significantly worse than before chemotherapy. There are often aversion to oil, nausea, vomiting, reduced appetite and reduced food intake. Therefore, it is advisable to adjust the dietary nutrition before chemoradiotherapy and increase the nutritional reserve to make the nutrition reach a better state. In order to increase the resistance of the body, the nutritional preparation of elemental diet or large molecule whole protein can be appropriately supplemented. Thick fluid and semi-liquid that are light, less oily and easy to digest and absorb should be given to maintain nutrition, so that patients can tolerate chemotherapy. According to the patient’s specific situation, a reasonable balanced diet should be chosen and a reasonable amount of energy supply should be formulated to meet the needs while avoiding excess. Protein, fat and sugar should account for 12%-15%, 25%-35% and 50% of the total energy respectively; animal and legume protein should account for 30%-50% of the total protein. Vitamin supply should be sufficient, and fresh vegetables and fruits should be consumed every day; the intake of minerals and trace elements should meet the needs of the body, and pay attention to the zinc-copper ratio and calcium-phosphorus ratio. Eat more foods with anti-tumor effects, such as fresh vegetables, fruits, dairy, soybean products and mushrooms, silver fungus, black fungus, etc. Drink more tea, quit smoking and limit alcohol. Those who have poor appetite in radiotherapy or chemotherapy should insist on eating less and more meals, and use commercially available enteral nutrition preparations if necessary.