Objective To investigate the safety and efficacy of mitral valve replacement combined with cryoablation Maze surgery in patients with atrial functional mitral regurgitation (AFMR). Methods From January 2014 to June 2020, patients with AFMR who underwent mitral valve replacement in our department were enrolled. They were divided into two groups, a cryoablation Maze group who received cryoablation Maze surgery during mitral valve replacement, and a non-cryoablation Maze group who did not receive cryoablation Maze surgery. The baseline data, surgical data, efficacy, and prognosis between the two groups were compared. Results Finally 85 patients were enrolled. There were 16 males and 24 females with an average age of 58.65±6.86 years in the cryoablation Maze group, and 24 males and 21 females with an average age of 61.29±8.30 years in the non-cryoablation Maze group. There was no statistical difference in baseline data between the two groups (P＞0.05). The aortic occlusion time and extracorporeal circulation time of the cryoablation Maze group were longer than those of the non-cryoablation Maze group with statistical differences (P＜0.01). There was no statistical difference in postoperative ICU retention time, ventilator assistance time, length of hospital stay, intraoperative blood loss, drainage volume on the first day or occurrence rate of complications (temporary pacemaker application, electrical cardioversion, thoracic puncture drainage, hospitalization death) between the two groups (P＞0.05). At the time of discharge, postoperative 3-month, 6-month, 12-month, and 24-month, the maintenance rates of sinus rhythm in the non-cryoablation Maze group were statistically different from those of the cryoablation Maze group (P＜0.001). Compared with the non-cryoablation Maze group, the decrease values of left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter and pulmonary artery systolic pressure were statistically different (P＜0.05). Postoperative cardiac function grading of both groups was grade Ⅰ or Ⅱ, which was significantly improved compared with preoperative level, but there was no statistical significance between the two groups (P＞0.05). There was no statistical difference in the incidence of adverse events during follow-up (P＞0.05). ConclusionCryoablation Maze surgery combined with mitral valve replacement is safe and effective in the treatment of AFMR patients, which is conducive to the recovery and maintenance of sinus rhythm, and is beneficial to the remodeling of the left atrium and left ventricle, the reduction of pulmonary systolic blood pressure, and the improvement of life quality of the patients.