Transcervical mediastinoscopy, with a small incision of about 2 cm in the patient’s neck, can play an extremely important diagnostic role. As an effective method for confirming the diagnosis of lung cancer and assessing lymph node staging, mediastinoscopy is currently the gold standard for clinical evaluation of mediastinal lymph node status in lung cancer. Although CT, MRI, as well as PET-CT and EBUS, which have been applied to clinical practice in recent years, can provide valuable evidence for lymph node staging before lung cancer treatment, they still cannot replace the diagnostic value of mediastinoscopy. 2. For peripheral lung lesions that cannot be reached by fibrinoscopy, the diagnosis can be confirmed by mediastinoscopic biopsy of metastatic lymph nodes.