When there is a large amount of pleural effusion, thoracentesis should be adopted, and the main steps include: 1. localization: take percussion, percussion to obvious turbid sounds, or ultrasound-guided localization, and select the deepest part of the effusion as the puncture point; 2. anesthesia: after selecting the puncture point, first of all, anesthesia should be administered, and the anesthesia should first anesthetize the skin, and more importantly, the pleura, to avoid pleural reactions; 3. puncture: fix the left hand Skin, the right hand into the puncture needle, puncture needle selection point as far as possible against the upper edge of the next intercostal space, because this can avoid piercing the intercostal vessels, resulting in bleeding in the thoracic cavity. When there is a feeling of falling out, you can draw back outward and see the drainage of pleural fluid, so that you can be sure that you have penetrated to the pleural fluid, so that the puncture can be performed; 4, dressing: when the puncture is finished, withdraw the needle, put the wound in sterile dressing, ask the patient to breathe oxygen, rest for 20 minutes to half an hour, and when the patient has no problem, he can go down to the ground.