Lung cancer combined with pericardial effusion is mostly due to the direct spread of tumor invading the pericardium or blocking the lymphatic drainage of the heart, resulting in pericardial effusion. In case of acute and large amount of pericardial effusion, the patient will suffer from cardiac compression, which is a direct threat to the patient’s life, and the easiest and most effective means is to perform pericardiocentesis drainage. The method of pericardial puncture and drainage is to select the bare area of the heart under the guidance of cardiac ultrasound, between the 4 and 5 ribs of the left edge of the sternum, with routine disinfection, local anesthesia, and a cavity towel, and then puncture and place a tube in the direction of the pericardium to extract the fluid under guidance, which can relieve the patient’s symptoms. The diagnosis of the cause of the disease can be clarified. In severe cases, surgical pericardial window drainage can be used to relieve the symptoms of pericardial compression.