The brain is an important metastatic site of cancer. Patients with brain metastasis, without formal treatment, are generally considered to have a survival period of about 1-2 months, and the main cause of death is brain edema and intracranial hypertension caused by cancer brain metastasis. However, patients with brain metastasis can significantly improve their survival and quality of life after active standardized treatment, such as dehydration anti-tumor therapy, radiotherapy, chemotherapy, targeted therapy, surgery, etc. After brain metastasis occurs, patients should actively cooperate with doctors for treatment and should not give up easily.