Mitral valve regurgitation is one of the most common heart valve diseases, of which secondary mitral valve regurgitation (sMR) has large proportion and poor prognosis. For patients who still have symptoms after the guideline-directed management and therapy, the effects of surgery are controversial, and transcatheter therapy provides a new option. Transcatheter edge-to-edge repair has become one of the recommended therapies by the guidelines, meanwhile transcatheter mitral valve annuloplasty and transcatheter mitral valve replacement are developing. However, the etiological mechanism of sMR is complex and diverse. There is an interaction between cardiac function and structure and sMR in dynamic change. It brings challenges to the selection of indicators and evaluation timing. The complex anatomical structure also makes it more difficult to design instruments and select surgical methods. This paper reviews the challenges and progress of transcatheter therapy for sMR.