Over the past 20 years, transcatheter mitral valve edge-to-edge repair (TEER) has become an important treatment option for patients with severe mitral regurgitation (MR) who are at high surgical risk. Initially, several landmark clinical studies established the basis of TEER for primary and secondary MR, but they only involved clinically stable patients with appropriate mitral valve anatomy. With the increasing experience of interventional therapy, the iteration of equipment and the improvement of intraoperative imaging technology, the scope of use of TEER has been continuously expanded, and its indications have been continuously expanded to more complex mitral valve lesions and clinical situations. Therefore, in clinical practice, selecting the appropriate device according to the individual anatomical characteristics of the patient can minimize MR and complications, thereby optimizing immediate and long-term prognosis. This article mainly introduces the pathogenesis and related mechanisms of MR, the main TEER devices and their clinical evidence, the limitations of TEER, and the future development direction.