Radiotherapy is one of the main treatment methods for patients with malignant tumors. The continuous progress of radiotherapy technology has greatly improved the survival rate of cancer patients and reduced the side effects of treatment. However the incidence of malnutrition is still high in cancer patients during radiotherapy especially in patients with head and neck cancer and gastrointestinal cancer. Therefore the implementation of whole-course nutritional management is particularly important for patients undergoing radiotherapy. In recent years nutritional intervention for cancer patients has attracted more and more attention. Many nutritional guidelines and Consensus for cancer patients have been published at home and abroad. In particular the nutritional norms and guiding principles for radiotherapy patients have been formulated which provide a solid theoretical basis for clinical implementation of nutritional screening assessment and treatment. This requires the guidance of a whole-process concept so as to effectively combine theory with practice to realize the whole-process nutrition management of tumor radiotherapy patients. Modern palliative care is an interdisciplinary subject that integrates medicine psychology ethics and sociology. It is also a people - oriented care system that improves the quality of life of patients. It is applicable to the entire course of any health-threatening disease especially in patients with tumors not just in the terminal stage. The application of palliative care in the whole nutritional management of radiotherapy patients will help to reduce the incidence of malnutrition and improve the quality of life of patients and the efficacy of radiotherapy.