Objective To explore the influencing factors of social avoidance in patients with nasopharyngeal cancer (NPC) undergoing radiotherapy, and to provide a basis for developing targeted nursing strategies for the same population. Methods A total of 12 NPC patients undergoing radiotherapy were selected as the participants by purposive sampling method.Descriptive qualitative research design was used for the study and semi-structured interviews were conducted to collect dada.Content analysis method was performed for data analysis and theme extraction. Results Three themes and seven sub-themes were extracted, namely, the inability to build an ideal self-image (including difficulties in face-to-face communication and potential negative evaluation), the weakening of self-value (ineffective response to reality, lower engagement in social activities, and the guilt of aggravating the family burden), and lack of social support (insufficient recognition support of relatives and friends, and insufficient professional support). Conclusion Medical staff should pay attention to the influencing factors of social avoidance of NPC patients, strengthen the coordination and cooperation of hospitals, communities and families, enhance patients′ sense of self-value, reduce their social psychological burden, and enable them to return to the social environment.