Pleural effusion after lung nodule surgery is considered to be caused by surgical trauma, infection and other factors. In lung nodule surgery, due to surgical injury, intraoperative washout of the chest cavity, a small amount of pleural effusion can occur after surgery, usually leave a drain for 1-3 days, and remove the drain after the drainage flow is less than 50-100 ml; after lobectomy, there is an increase in negative pressure in the chest cavity, which can also cause pleural fluid phenomenon; after lung nodule surgery, there is an infection, which can cause an increase in inflammatory exudate in the chest cavity, and there is a pleural effusion. If the patient’s pleural effusion after lung nodule surgery is relatively small, it can be self-absorbed and generally can not do special treatment; however, if the amount of effusion is relatively large and accompanied by obvious discomfort, it is recommended to go to the hospital in time for examination and diagnosis, and under the guidance of a professional doctor, combined with the individual situation, choose thoracocentesis to extract the fluid and other methods of treatment, so as to avoid misunderstanding the condition of the aggravation of the symptoms.