How to deal with pleural effusion mainly depends on the amount of pleural effusion and the nature of the effusion. If it is a general leaking pleural effusion and the amount is relatively small, invasive treatment is generally unnecessary, focusing on treatment of the primary disease, such as correction of hypoproteinemia and cardiac failure; if the amount is large, thoracentesis and drainage can be considered on the basis of treatment of the primary disease. Second, if it is infected pleural effusion, regardless of whether the amount is large or small, in principle, the pleural effusion should be drained as much as possible and systematic anti-inflammatory treatment should be carried out at the same time. Third, if it is a malignant pleural effusion caused by tumor invasion of the pleura, on the basis of anti-tumor treatment, the effusion can be drained, and at the same time, pro-adhesion drugs can be injected into the pleural cavity to promote pleural cavity atresia to reduce the exudation of pleural effusion.