Objective To explore the effects of a nutritional assistant nursing-mode in head and neck cancer patients undergoing radiotherapy whose degree of implementation of nutrition programmes and impact on nutrition status and physical and mental health. Method 138 patients with head and neck cancer in Nanjing Drum Tower Hospital from June 2018 to December 2021 were selected and randomly divided into control group n = 72 and observation group n = 66 . The intervention group patients adopted the nursing-mode of a nutritional assistant role. In the control group was treated with routine nursing-mode. All patients received radical concurrent chemoradiotherapy. Then the nutrient intaking nutritional indexes the degree of anxiety and depression as well as quality of life were compared between the two groups. Result The energies of the two groups were decreased while the indexes of intervention group were better at other time points but there was no statistical significance P> 0. 05 . The proteins intakes of the intervention group were better between two groups P<0. 05 . The HADS and KPS scores of the intervention group were better P< 0. 05 . The indexes of serum albumin and weight in the intervention group were better except CRP P< 0. 05 . Conclusion In the treatment of head and neck cancer the nursing-mode of a nutritional assistant role may help to maintain patients' energy as well as protein intaking. In addition it may also alleviate nutritional status and the physical and psychological healthy states.