Pleural effusion is a common clinical condition in which the fluid collected in the pleural cavity exceeds the normal range. It requires both thoracentesis and aspiration to alleviate the symptoms and treatment for the cause, and different treatment options are chosen according to the cause of different morbidities. Pleural effusion is divided into two types: leakage and exudate, and the treatment of the cause of pleural effusion is very important. Leaky fluid can be absorbed on its own after etiologic treatment. Exudate is common in diseases such as pneumonia, cancer, malignant pleural effusion, abscess chest, tuberculous pleurisy, etc. The principles of management of exudative pleurisy mainly refer to the treatment of the cause, such as tuberculous pleurisy, most of the anti-tuberculosis treatment, etc. A small pleural effusion usually does not require pleural aspiration, but a small amount of pleural effusion can be extracted for diagnostic puncture. Pleural effusion more than medium as well as medium fluid or more should be treated with aspiration, which can reopen the lung, reposition the mediastinum and prevent pleural thickening. Sepsis is commonly secondary to infection and trauma, and the pathogens are mainly anaerobic bacteria, tuberculosis, staphylococcus, and actinomycetes. The main manifestations are high fever, chest distension and pain. Anti-infective treatment against the pathogen can be intra-thoracic administration of drugs and repeated pus extraction or closed drainage. Malignant pleural effusion, which mainly occurs in lung cancer and breast cancer, needs to be treated with surgery and chemotherapy according to the condition, and pleural effusion is not effective after treatment. In short, the occurrence of pleural effusion requires a clear diagnosis of the cause of the disease and treatment of the cause and symptomatic treatment. Do not do strenuous exercise and pay attention to rest.