Atrial fibrillation causing pericardial effusion should be treated medically for atrial fibrillation, commonly with amiodarone, electrical cardioversion if necessary, and pericardiocentesis for pericardial effusion. Atrial fibrillation refers to atrial fibrillation, which is the disappearance of ordered electrical activity in the atria and its replacement with disordered fibrillation waves, which can be diagnosed by electrocardiogram, and untreated atrial fibrillation can lead to ventricular fibrillation, which is life-threatening. Treatment of pericardial effusion caused by atrial fibrillation first to treat the cause of atrial fibrillation, need to seek medical attention in a timely manner, mainly to restore sinus rhythm, commonly used drugs such as amiodarone, propafenone, etc., and electrical cardioversion if necessary. Pericardial effusion refers to the accumulation of fluid in the pericardial cavity due to a variety of factors, so that the heart diastolic restriction, reduced efflux, in the control of atrial fibrillation after the use of pericardial puncture aspiration drainage, necessary surgical drainage. When atrial fibrillation causes pericardial effusion, it should be promptly consulted and treated as prescribed by the doctor.