The duration of pleural effusion drainage is 7~9 days and is related to the cause and severity of the disease. Drainage of less than 100ml in one day can usually be removed, and it is removed on the 2nd~3rd day after closed chest drainage. 1. Rib fracture: If the pleural effusion is caused by rib fracture, the amount is usually small, and can be drained by syringe or closed chest drain, and the drainage can be completed in about 1 day. 2. Tuberculous pleural effusion: in case of tuberculous pleural effusion, it is necessary to use anti-tuberculous drugs to alleviate the symptoms while draining the pleural effusion, which usually takes about 3 days. 3. Malignant tumors: if the pleural effusion caused by malignant tumors, the amount is relatively large, the first effusion does not exceed 600 ml, and each subsequent extraction does not exceed 1000 ml, for these patients, the drainage of pleural effusion in order to alleviate respiratory distress, may be a long period of time to retain the drainage tube, and when respiratory distress occurs, appropriate drainage. 4. Other: for chest surgery, such as postoperative drainage more, in reaching the standard of drainage less than 100 ml in one day, and continue for about 3 days choose to pull the tube, about drainage time for 7-9 days, some patients may be drainage time is less than 7 days, depending on the amount of postoperative drainage to decide. How long it takes to drain pleural effusion needs to be decided by the doctor according to the overall condition of the patient.