Once brain metastasis occurs in lung cancer, its clinical stage is stage IV, which already belongs to advanced stage of lung cancer. Although it is still difficult to achieve clinical cure after effective treatment, patients with advanced lung cancer can have their clinical symptoms effectively relieved, improve their quality of life and effectively prolong their survival time after effective treatment in the late stage. In addition to the aggravation of respiratory symptoms in the primary foci of lung cancer, patients with brain metastases may also experience increased intracranial pressure caused by brain metastases and neurological damage, such as headache, vomiting, hemiplegia, aphasia, abnormal gait and ataxia. For the treatment of lung cancer brain metastasis, besides systemic chemotherapy and targeted therapy, local gamma knife or whole brain radiotherapy can also be given to treat brain metastases.