Lung cancer is divided into small cell lung cancer and non-small cell lung cancer, and adenocarcinoma in small cell lung cancer and non-small cell lung cancer is prone to metastasis. The clinical manifestations of lung cancer are not exactly similar depending on the metastatic sites, for example, metastasis to the medulla oblongata region of the central nervous system tends to cause respiratory center abnormalities. The tumor is particularly large, and metastasis compressing the hypothalamus is easy to form brain herniation. There is also the sudden appearance of cerebral hemorrhage, and the mortality rate of patients is particularly high. For brain metastasis of lung cancer, it should be treated with mannitol dehydration hormone therapy, as well as the most applied therapeutic measures such as radiotherapy and particle intervention at present. In conclusion, after brain metastasis of lung cancer, the survival period of patients is significantly shortened.