Atrial fibrillation (AF), one of the most common arrhythmias, accounts greatly for the morbidity and mortality of cardiovascular diseases. Epicardial adipose tissue (EAT), a kind of special adipose tissue, is anatomically located between the visceral pericardium and myocardium. EAT is involved in the development and maintenance of AF, but the mechanisms have not been fully elaborated. EAT-derived extracellular vehicles (EVs) have gained much attention recently. This paper mainly reviews the characteristics and quantitative detections of EAT, especially the role of EVs in the development of AF and its relationship with myocardial structural and electrical remodeling, so as to provide new insights on the pathogenesis of AF and reference for the treatment of AF in the future.