Atrial fibrillation is the most common arrhythmia in clinical practice and is closely related to stroke and thromboembolism. Atrial fibrillation increases the risk of thrombosis by disrupting physiological haemostatic mechanisms that are understood by reference to Virchow′s triad of “abnormal blood constituents”“vessel wall abnormalities” and “abnormal blood flow”. Left atrial appendage is the main part of atrial fibrillation due to its complex morphological structure and special functional characteristics. A better understanding of the various factors of atrial fibrillation thrombosis contributes to a better stratification of the risk of atrial fibrillation thrombosis and its timely and effective treatment.