After lung cancer spreads, it can be treated with various therapies such as surgery, radiotherapy, chemotherapy, targeted therapy, immunotherapy and so on according to its condition. Lung cancer is a malignant tumor of respiratory system caused by heredity, smoking, environment and other factors. When the disease develops to the late stage, distant metastasis and proliferation often occur, such as liver metastasis, bone metastasis, brain metastasis, etc. At this period, the treatment can be decided according to the specific metastatic situation. For single metastatic lesions that can be tolerated by the patient, surgical resection is feasible, followed by radiotherapy and chemotherapy; for those without surgical opportunities, non-surgical therapies such as radiotherapy, chemotherapy, targeting and immunotherapy are feasible. After active treatment, the five-year survival rate of patients in this period is about 5%.