Thoracoscopic technology, as a new diagnostic technique, has become increasingly mature and is widely used and favored by clinicians. Thoracoscopic techniques are divided into medical thoracoscopic techniques and surgical thoracoscopic techniques, both of which have their own advantages and disadvantages, as well as their own focus. Generally speaking, medical thoracoscopy focuses on diagnosis while surgical thoracoscopy focuses on treatment; medical thoracoscopy can be done in the endoscopy room with simple equipment and local anesthesia, while surgical thoracoscopy requires double-lumen tracheal intubation in the operating room with general anesthesia and relatively complicated equipment requirements, etc. Then, under what circumstances should thoracoscopy be performed for patients with diagnosed lung cancer? Firstly, to assist the clinical staging of lung cancer. For lung cancer patients whose staging is not clear and precise, surgical thoracoscopy can be considered to determine whether there are mediastinal hilar lymph node metastases, because sometimes enlarged lymph nodes on imaging are not exactly equal to metastatic lymph nodes, and non-enlarged lymph nodes are not exactly equal to no lymph node metastases, at this time, surgical thoracoscopy can help to obtain surgical pathology to confirm the diagnosis. For patients with combined pleural nodules or pleural effusion, medical thoracoscopy can be considered to clarify whether there is pleural metastasis and whether it is malignant pleural effusion, so as to assist lung cancer staging. Secondly, it can assist in the treatment of lung cancer. For lung cancer patients with indications, especially early peripheral lung cancer patients, surgical thoracoscopic surgery can be considered, which is minimally invasive thoracic surgery to remove tumor without opening the chest. Furthermore, for lung cancer patients with combined malignant pleural effusion, medical thoracoscopy technique can be considered to spray dry talcum powder directly under the thoracoscope to adhere and fix the pleura, so as to alleviate the symptoms and pain, eliminate the trouble of malignant pleural effusion for advanced lung cancer patients once and for all, and improve the quality of life.