The diagnosis of lung cancer can be seen in both respiratory medicine and thoracic surgery. For soft tissue masses found in the lung, fiberoptic bronchoscopy can be done to clarify the nature of the lung lesion. Fiberoptic bronchoscopy is usually performed in respiratory medicine, while small lesions requiring surgical resection can be performed in thoracic surgery. Therefore, the diagnosis of lung cancer can be first diagnosed in respiratory department or in thoracic surgery, especially peripheral type lung cancer is more the advantage of thoracic surgery, which has some advantages in diagnosing lung cancer. At the same time, after clarification, it can be assessed whether surgery can be performed or not, because surgery is the first choice for lung cancer treatment, regardless of any conditions, and surgery can be performed as much as possible. Unless it is combined with distant metastasis or locally advanced, it is impossible to do surgery before considering conservative medical treatment.