Due to the special anatomical location of the mediastinum, there is no natural channel to connect with the outside world, which makes the diagnosis of mediastinal masses, especially mediastinal lesions, often more difficult. The treatment varies greatly depending on the cause. It is difficult to obtain a clear pathological diagnosis by general examination methods, so mediastinal mass lesions often become a difficult point in diagnosis, which can easily lead to misdiagnosis and mistreatment, making such diseases a difficult point in clinical work. Mediastinoscopy is an effective means for the examination of upper mediastinal diseases, and it is still one of the most important means for the diagnosis and treatment of mediastinal diseases and preoperative pathological staging of lung cancer because of its advantages of small trauma, safety and reliable sampling. According to a large amount of clinical data at home and abroad, the complication rate of mediastinoscopic surgery is less than 2.5%. In recent years, with the continuous development of modern science and technology and medical equipment, the emergence of TV mediastinoscopy has greatly improved the clarity of the mediastinoscopic field and increased the safety and accuracy of the operation. Which chest diseases can be diagnosed and treated with TV mediastinoscopy? At present, the most suitable diseases for TV mediastinoscopy are: ① diagnosis of difficult mediastinal diseases; ② clear preoperative staging and diagnosis of lung cancer; ③ treatment of mediastinal diseases, such as mediastinal cystectomy, mediastinal metastatic lymph node removal, drainage or removal of mediastinal accumulation (hematoma, celiac disease, abscess), etc. At present, TV mediastinoscopic surgery has become a routine method for the diagnosis of difficult mediastinal diseases and the staging of lung cancer in developed countries such as Europe and the United States. In the past 4 years, due to various reasons, China’s thoracic surgeons lack sufficient knowledge of mediastinoscopic surgery, coupled with technical and equipment limitations, this technology has not been well developed in China, and only a few hospitals have carried out limited mediastinoscopic surgery, lagging far behind developed countries such as the United States and Europe in terms of the number of surgical cases, types of surgery and popularity. As the only specialized hospital for thoracic diseases in the province, the Department of Thoracic Surgery of Nanjing Chest Hospital has rich experience in the treatment of thoracic diseases. We took the lead in introducing TV mediastinoscopy in the province, accumulated rich experience in TV mediastinoscopy surgery, and successively carried out operations such as parasternal mediastinoscopy and single operation hole through intercostal space to treat pleural effusion in the province.