Abstract: Lung cancer is the second most common cancer worldwide, and 40% of patients with non-small cell lung cancer may develop brain metastases. Radiotherapy is a classic treatment for brain metastases, and immunotherapy has emerged for advanced non-small cell lung cancer. This article discusses the theoretical bases, clinical efficacy and safety, and the optimum timing of radiotherapy combined with immunotherapy for brain metastases from non-small cell lung cancer to provide reference for clinical practice and scientific research.