Objective To investigate the clinical efficacy and safety of linear accelerator radiotherapy in elderly patients with non-small cell lung cancer (NSCLC) and to provide a reference for clinical treatment. Methods A total of 60 elderly patients with NSCLC admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine from January 2020 to October 2022 were selected and randomly divided into an intervention group (linear accelerator radiotherapy) and a control group (conventional radiotherapy), with 30 patients in each group. The short-term efficacy (objective efficacy, objective response rate, disease control rate), long-term efficacy (progression-free survival, overall survival), and incidence of radiotherapy-related adverse events were assessed between the two groups. Results The objective efficacy in the intervention group was significantly better than that in the control group (Z=2.163, P=0.031), and the objective response rate was significantly higher than that of the control group (63.3% vs 36.7%, χ2=4.267, P=0.039). The median progression-free survival (9.8 months vs 6.5 months, χ2=6.481, P=0.011) and median overall survival (21.4 months vs 16.8 months, χ2=4.920, P=0.027) were both significantly longer in the intervention group compared to the control group. There was no statistically significant difference between the two groups in the incidence of radiotherapyrelated adverse events (P >0.05). Conclusion Linear accelerator radiotherapy can significantly improve both the short-term response rate and the long-term survival rate in elderly patients with NSCLC without increasing the risk of treatment-related adverse events, demonstrating good safety.