The survival period of lung cancer after brain metastasis is related to the treatment effect of the patient’s primary disease and individual factors, and cannot be generalized. Brain metastasis is a relatively common metastatic site of lung cancer and is often one of the causes of death from lung cancer. Brain metastasis of lung cancer will lead to dizziness, headache, nausea and vomiting. After brain metastasis occurs, the survival period of lung cancer patients is generally maintained at about 6 months, which can be extended to 1-2 years after treatment with good efficacy, but if brain metastasis occurs without corresponding treatment, the survival period is generally about 3 months. The survival period of brain metastasis from lung cancer is also related to the age of the patient, and the survival period of young people will be longer than that of old people. After brain metastasis occurs in lung cancer patients, whole brain radiotherapy and stereotactic radiation therapy for metastases need to be performed in a timely manner. Active cooperation with treatment can help prolong survival.