Thromboembolic complications are a major cause of disability and death in atrial fibrillation, and prevention of embolic events in patients with atrial fibrillation is an important issue in the treatment of atrial fibrillation. Oral anticoagulants are currently the most effective way to prevent thromboembolic complications in AF, and adjusted doses of warfarin may result in a relative risk of stroke in AF. However, the narrow safety window of warfarin therapy is influenced by many factors such as diet and medications, and frequent monitoring of the international normalized ratio (INR) is required, resulting in poor patient compliance with the medication and high discontinuation rates with long-term application. A recent analysis of data from more than 130,000 warfarin applications in the United States showed that the mean time to INR in the therapeutic range was only 53.7%. Even in patients whose INR is maintained within reasonable limits, there is growing evidence that long-term warfarin application leads to increased cerebral microhemorrhage and may be associated with a risk of dementia. A series of clinical studies in recent years have shown that new oral anticoagulants (NOACs) such as dabigatran, rivaroxaban, and apixaban are no less effective than warfarin, do not require routine monitoring, and do not increase the risk of bleeding in patients. However, these drugs also have shortcomings such as high price, unknown safety of long-term dosing, high incidence of gastrointestinal adverse reactions, and still high discontinuation rates in clinical trials. In addition, most of the people at high risk of embolism are also at high risk of bleeding, and the choice of means to prevent embolic events in patients at high risk of bleeding or with contraindications to anticoagulation is an important issue that is continuously explored in clinical practice. The left auricle is a remnant accessory structure of the embryonic left atrium with a large number of unevenly distributed comb-like muscles in its inner wall, which is the structural basis for thrombus formation. Immunohistochemical studies on the left auricle have shown that Von Willebrand (vW) factor expression is increased in the overloaded left auricle, thereby predisposing it to platelet adhesion and thrombus formation. Significantly reduced or even loss of function of left auricular blood flow in atrial fibrillation provides the hemodynamic basis for thrombus formation. Transesophageal ultrasound revealed that 90% of intra-atrial thrombi in patients with nonvalvular atrial fibrillation were located in the left ear, and the SPAF III study, which analyzed 786 patients with nonvalvular atrial fibrillation who underwent transesophageal ultrasound, showed that left ear thrombus and reduced peak left ear flow velocity were independent predictors of thromboembolic events. This evidence suggests that prevention of left-ear thrombosis may reduce the incidence of thromboembolic events in atrial fibrillation. Previous clinical practice has shown that resection of the left ear in conjunction with valve replacement or angioplasty during surgical procedures, particularly in patients with rheumatic heart valve disease, may reduce the incidence of stroke. The current surgical management of the left auricle includes transthoracic resection/ligation of the left auricle under direct vision and transthoracoscopic resection/ligation of the left auricle. The surgical treatment methods are difficult to promote in the clinic because of the high trauma and risk. With advances in cardiovascular interventions and device development, percutaneous left auricular occlusion for stroke prevention has received increasing attention. In the PROTECT-AF study, all enrolled patients were not contraindicated to take warfarin, and all patients who completed the blocker in the PROTECT-AF study design were required to take warfarin for at least 45 days. The ASAP trial provided a preliminary answer to the question of whether left-ear blockade is safe and effective in patients with high-risk atrial fibrillation who are contraindicated to take warfarin. The study enrolled 125 patients with atrial fibrillation at high risk of stroke for whom warfarin was contraindicated, who took clopidogrel for 6 months after completion of left ear occlusion and aspirin for life. The results of the ASAP trial suggest that left-ear occlusion without warfarin is safe and feasible, and that left-ear occlusion can be used as an alternative to warfarin in patients with atrial fibrillation who have contraindications to warfarin use. The left ear block can be used as an alternative treatment for patients with contraindications to warfarin. In the 2012 ESC guideline update on the management of atrial fibrillation, left ear occlusion was recommended for patients with atrial fibrillation who have a contraindication to long-term oral warfarin therapy and are at high risk of embolism (IIb, B). in June 2014, the UK NICE guideline on the management of patients with atrial fibrillation was updated and for the first time left ear occlusion was recommended as a treatment for patients who have a contraindication to anticoagulation or are intolerant to anticoagulation. Although the 2014 AHA/ACC/HRS guideline on atrial fibrillation reviewed studies related to several left-ear occlusion devices, it did not give a corresponding recommendation, stating only that patients with atrial fibrillation undergoing cardiac surgery may have their left ear removed at the same time (IIb, C). The reasons for this are that the new guidelines do not recommend left-ear occlusion because the evidence is not yet sufficient and there are concerns about the perioperative safety of left-ear occlusion. However, with the publication of the results of studies such as PROTECT-AF and longer follow-up, it is believed that left-ear occlusion will play an important role in the prevention of atrial fibrillation embolism. New technologies are driven by clinical demand, and the advent of left-ear occlusion certainly brings new hope for embolic prophylaxis in AF in the post-warfarin era. For patients at high risk of stroke and for whom oral anticoagulation is contraindicated or not tolerated, percutaneous left auricular occlusion may be one of the most appropriate treatments. The clinical benefit of left-ear occlusion may be particularly significant in patients with a previous history of stroke and in those older than 75 years of age. In addition, left-ear occlusion may be considered in patients with embolic events despite the standard use of oral anticoagulation, after excluding other sources of embolism, and as a complement to NOAC in patients with previous intracranial hemorrhage or combined intracranial vascular malformations. We also need to note that left-ear occlusion is highly dependent on operator experience, and complications such as pericardial tamponade, thrombosis of the occluder, and residual leakage reported in previous studies need to be taken into account. In addition, the hemodynamic and neuroendocrine effects of occlusion on patients need long-term follow-up and observation. Nevertheless, as an indispensable and important tool in the comprehensive treatment of patients with atrial fibrillation, left auricular occlusion still has a broad clinical application prospect.