Lung cancer is a very common malignant tumor of the respiratory system. The exact process of lung cancer formation is still unclear, and it may go through some benign lung lesions, such as lung nodules, then precancerous lung lesions, and finally lung cancer. Lung cancer may have no obvious symptoms in the early stage, or it may show cough, sputum, hemoptysis, etc. Generally, occupying lesions can be detected through lung CT, and further percutaneous lung aspiration biopsy or bronchoscopy can be done to confirm whether it is lung cancer. For early and middle stage lung cancer, radical surgery is the first step, followed by radiotherapy and chemotherapy after surgery. If lung cancer is found in the middle or late stage, there is no way to operate, and only palliative radiotherapy and chemotherapy can be considered.