The treatments for pericardial effusion after early surgery for lung cancer include close observation and pericardiocentesis. Most of the pericardial effusions after early postoperative lung cancer surgery are small amount of fluid, which may be related to surgical stress reaction, and most of them also have no obvious clinical symptoms. For pericardial effusion without obvious symptoms, it can be handled clinically by observation, and most of it will be gradually absorbed without affecting the patient’s cardiac function. Larger amounts of pericardial effusion will compress the heart, causing symptoms of chest tightness and shortness of breath, panic, and rapid heartbeat. At this time, pericardiocentesis should be performed urgently to remove the pericardial effusion and relieve the pressure on the heart, which is also the most effective treatment.