Inclusion Criteria:  Severe mitral valve regurgitation ≥ 3+ (moderate-to-severe mitral regurgitation disease);  Patients with high or prohibitive risk for conventional open thoracic surgery as defined by STS risk scoring result; subjects who are judged as not tolerating mitral valve surgery due to STS procedural mortality risk ≥ 8% for mitral valve replacement or presence of any of the following risk factors:  Porcelain aorta or active ascending aortic atheroma Prior radiation therapy to mediastinum History of mediastinitis Left ventricular ejection fraction (LVEF) < 40% Presence of unobstructed coronary artery bypass graft History of 2 or more cardiothoracic surgeries Liver cirrhosis Other surgical risk factors Degenerated MR patients, or functional MR patients who have received guideline-directed medical therapy (GDMT therapy) Age ≥ 18 years, male or female; Patients who are at extremely high risk or not suitable for conventional mitral valve surgery, as assessed by a multidisciplinary heart team (including at least one cardiac surgeon and one cardiologist); Anatomically suitable for transcatheter mitral valve repair by edge-to-edge technique and can be treated by the SQ-Kyrin device; Patients who can understand the objectives of the trial, volunteer to participate in the study, sign the informed consent form, and are willing to receive related examinations and clinical follow-up.  Exclusion Criteria:  History of cardiac and mitral valve surgeries; Infective endocarditis or evidence of active infection; Mitral valve stenosis; Severe uncontrolled coronary artery disease; Pulmonary artery hypertension (systolic pulmonary artery pressure > 70 mmHg); Severe right cardiac insufficiency; LVEF < 30%; Cardiac function of NYHA Class IV; Patient is extremely week to tolerate surgery under general anesthesia, or in a shock state indicating circulatory support; Hypertrophic cardiomyopathy, restrictive cardiomyopathy, or constrictive pericarditis; Chronic dialysis; Definite coagulation disorder and severe coagulation system diseases; Clear contraindications for use of anticoagulants; Cerebral stroke or transient ischemic attack in the past 30 days; Any cardiac mass, left ventricular or atrial thrombosis identified by echocardiography; Other valve diseases that requiring surgery or intervention; Severe macrovascular disease requiring surgical treatment; Treatment-naive carotid artery stenosis > 70%; Imaging evidence of inappropriate cardiac and valve anatomy; Known hypersensitivity to contrast media, and nickel-titanium memory alloy products; Severe nervous system disorder compromising the cognitive ability; Life expectancy < 12 months; Severe thorax deformity; Pregnant and lactating women.