Objective The study was to investigate the effect of psychological intervention on emotion and long-term effect of patients with nasopharyngeal cancer treated with radiotherapy. Methods A total of 100 patients with nasopharyngeal cancer were divided into the psychological intervention group and the control group with 50 cases in each. The patients in the psychological intervention group were given psychological intervention besides receiving radiotherapy and routine nursing which were similar to the control group. Anxiety score and depression score as well as survival rates before and after radiotherapy between two groups were compared. Results There was no difference in anxiety score and depression score between two groups before radiotherapy, but after radiotherapy, the anxiety score and depression score were more remarkably reduced in the psychological intervention group than in the control group. The 1, 3, 5-year overall survival rates were 100.0%, 94.0%, 85.9% respectively in the psychological intervention group, and were 96.0%, 85.6%, 70.7% respectively in the control group. Duration from the end of radiotherapy to relapse were (32.22±16.82) months in th psychological intervention group and (20.73±13.06) months in the control group. Conclusions Psychological intervention can improve anxiety and depression and shows a tendency to defer the occurrence of relapse and to improve the survival rate in patients with nasopharyngeal cancer treated with radiotherapy. The further research need to be done.