Mediastinal tumor is a common chest disease, characterized by insidious onset, non-specific symptoms and deep lesion location, which is difficult to be detected by general physical examination and requires CT or MRI to be diagnosed. Anterior mediastinal tumors are often complicated by severe myasthenia gravis, and in severe cases, life threatening due to respiratory failure. Posterior mediastinal tumors often originate from the nervous system, and in serious cases, compression of the spinal cord leads to paraplegia. Therefore, for the diagnosis and treatment of mediastinal tumors, regular physical examination, early detection, early treatment and satisfactory surgical results are required. For most mediastinal tumors, our department adopts high-definition thoracoscopic minimally invasive surgery, which does not destroy the stability of the thorax, with good results and fast recovery. The surgical incision is small and beautiful (about 2cm), and there is no need to remove stitches after surgery.