Objective To explore the potential categories and influencing factors of frailty features in patients undergoing radiotherapy for lung cancer, and to provide reference for personalized and precise symptom management of frailty in patients undergoing radiotherapy for lung cancer. Methods A total of 241 lung cancer radiotherapy patients were selected by convenient sampling method. General data questionnaire, Fried Frailty Phenotype Scale, Barthel Index Scale and Nutritional Risk Screening 2002 were used for investigation. Potential category analysis was used to identify the potential category characteristics of lung cancer radiotherapy patients, and multi-classification logistic regression analysis was used to explore the influencing factors of the potential category of lung cancer. Results The incidence of frailty in lung cancer radiotherapy patients was 55.19%, and frailty score was 2.00 (1.00,4.00) points. Frailty in lung cancer radiotherapy patients presented three potential categories:pre-frailty group (30.3%), frailty-non-intentional weight loss group (35.7%), and severe frailty-activity decline group (34.0%). The number of radiotherapy, Barthel index, nutritional risk score and age were the influencing factors for the potential type of frailty in lung cancer radiotherapy patients (all P<0.05). Conclusion There is group heterogeneity in frailty in patients undergoing radiotherapy for lung cancer, and clinical staff should focus on the assessment and management of frailty in patients with low Barthel Index score, nutritional risk score ≥3, high number of radiotherapy sessions, and advanced age，aiming to reduce the level of frailty in patients.