Pulmonary effusion, also known as pleural effusion, usually takes 2 to 14 days to pump in patients with pleural effusion, but there is no clear clinical data. There are many causes of pleural effusion, such as increased hydrostatic pressure in the pleural capillaries, increased permeability of the pleura, and injury. In clinical practice, one of the treatments for pleural effusion is thoracentesis, in which the pleural cavity between the lungs and the chest wall is punctured to evacuate the pleural fluid and relieve the discomfort of chest tightness and chest pain caused by the disease. If the patient has a small amount of fluid in the pleural cavity, a thoracentesis is performed for about 2 days. If the amount of pleural fluid is large, the time needed to perform a closed chest drain is around 14 days. Therefore, the time of pleural effusion pumping is not fixed and needs to be judged according to the actual situation of the patient. During the treatment period, patients need to strengthen the local skin care, keep the local clean and dry, prevent the occurrence of infection, if necessary, can follow the doctor’s instructions to take penicillin, cefixime and other anti-infective drugs. It is recommended that patients with pleural effusion actively cooperate with the doctor’s treatment, in order to promote the recovery of health.