Traditional diagnostic methods, such as conventional thoracentesis, have technical limitations, resulting in about a quarter of patients with pleural diseases not being able to obtain a clear diagnosis, thus delaying the treatment of the disease; in addition, diseases such as acute abscess chest, intractable pleural effusion, and pneumothorax are often poorly treated only through conservative internal medicine. Internal electronic thoracoscopy is a safe and effective minimally invasive treatment technology, and for the above-mentioned patients, the use of internal thoracoscopy for examination and treatment is of irreplaceable importance. Endoscopic thoracoscopy only requires a skin incision of about 1 cm in the chest wall of the patient, and the pleural lesions can be observed under direct vision using the thoracoscope, which can reach the wall pleura, dirty pleura, diaphragmatic pleura and mediastinal pleura that cannot be reached by conventional examination. In addition to clarifying the diagnosis, internal thoracoscopy can also separate the wrapped adhesion zone in the chest cavity, flush and drain the pus moss and pus in the chest cavity for patients with acute abscess chest. For malignant or benign intractable pleural effusion, pleural adhesions can be promoted by spraying adhesives under the thoracoscope to reduce the formation of pleural fluid. For recalcitrant pneumothorax, treatment can be performed by observing the pleural rupture under thoracoscopy, separating the pleural adhesion bands that affect the healing of the rupture, and spraying pleural adhesives. After the operation, a closed drainage tube routinely placed into the chest cavity can also serve as a treatment to drain the pleural fluid, inject drugs into the chest cavity or flush the chest cavity. What is the proper way to perform closed drainage of the chest cavity after medical thoracoscopy? First, the water seal bottle or drainage bag should be placed 60~100 cm below the level of the placement tube. It should not be higher than the incision plane to prevent backflow of drainage fluid leading to infection. Secondly, it is advisable to adopt a semi-sitting position after surgery, and you can take a lateral position when turning over, and pay attention to avoid pressure or distortion of the catheter. Once again, when the condition improves and activity can be tolerated, you can get out of bed with the tube. When moving, the drainage bag or bottle should be placed 60 cm below the level of the tube and not higher than the incision plane, and attention should be paid to avoid dislodging the connection. When changing clothes, turning in bed and getting out of bed to use the toilet, special attention should be paid to prevent accidental extraction of the drainage tube. Finally, during the drainage period, the drainage tube should be kept open. If the drainage bottle is found to be cracked or the connection is dislodged, the upper end of the drainage tube should be clamped immediately and the medical staff should be notified to deal with it in order to avoid causing pneumothorax.