A pleural fluid puncture usually does not injure the lungs, but there is a possibility of injury to the lungs if it is done improperly. The puncture site of wall thoracentesis for pleural effusion is in the 6th and 7th intercostal space in the mid-axillary and posterior axillary lines, and the drain tube needs to be punctured about 2 cm to 3 cm into the chest cavity. If the puncture site is chosen incorrectly or the depth of the puncture is greater than 3 cm, it may lead to lung injury and cause pneumothorax. In most cases, the operation steps are scientific and meticulous, will not damage the lungs, due to the 6th and 7th rib space away from the lungs, there is a part of the gap between the thoracic cavity, all can avoid lung injury. If the patient has symptoms of dyspnea, it is recommended to go to respiratory medicine or thoracic surgery in time, so as not to delay the treatment and aggravate the condition.