Prophylactic brain radiotherapy can significantly reduce the probability of brain metastases from small cell lung cancer. Prophylactic brain radiotherapy should be administered to limited small cell lung cancer in complete remission after chemotherapy, and patients with extensive metastases who have achieved complete remission with induction chemotherapy may also benefit from prophylactic brain radiotherapy. Radiotherapy is less effective for brain metastases that appear after chemotherapy, and the metastases will still progress after radiotherapy, and increasing the dose of radiotherapy can prolong the remission time. The immediate remission rate after radiotherapy for small cell lung cancer is 60%-80%, but the duration is short. The median survival of patients with brain metastases is only 4-5 months after diagnosis. Whole-brain radiotherapy is the standard treatment for patients, and certain chemotherapy regimens (e.g., carboplatin + teniposide, VPC regimen of onychothioside + cisplatin + simustine, VmP regimen of onychothioside + cisplatin, and systemic chemotherapy regimen of intrathecal methotrexate and dexamethasone) are also effective.