Objective To investigate the effects and complications of mitral valve membrane replacement surgery with preservation of mitral valve subvalvular structure on cardiac and valve function. Methods A total of 84 patients receiving mitral valve membrane replacement surgery with preserved mitral valve subvalvular structure in the First Affiliated Hospital of Soochow University from August 2019 to July 2022 were selected as the observation group， and 68 patients receiving mitral valve membrane replacement surgery without preservingmitral valve subvalvular structure were selected as the control group. The surgical indicators， comorbidities， preoperative and postoperative cardiac function，and mitral valve hemodynamic parameters were compared between the two groups. Results There was no statistically significant difference between the observation group and the control group in terms of surgical history， extracorporeal circulation time， aortic occlusion time， postoperative mechanical ventilation time， ICU retention time， and postoperative hospitalization time （P > 0.05）. At 1， 3， and 6 months after surgery， the left ventricular end systolic diameter （LVESD） and left ventricular end diastolic diameter （LVEDD） in the observation group were significantly lower than those in the control group （P < 0.05）， while the left ventricular short axis shortening rate （LVFS） was significantly higher than that in the control group （P < 0.05）. There was no statistically significant difference in left ventricular ejection fraction （LVEF） between the observation group and the control group at 1， 3， and 6 months after surgery （P > 0.05）. There was no statistically significant difference （P > 0.05） in the peak mitral valve velocity （Vmax）， maximum pressure gradient difference （PGmax）， and mean pressure gradient difference （PGmean） between the observation group and the control group at 1， 3， and 6 months after surgery. There was no statistically significant difference in creatine kinase isoenzyme （CK-MB） and N-terminal precursor brain natriuretic peptide （NT-proBNP） between the observation group and the control group at 1， 3， and 6 months after surgery （P > 0.05）. There was no statistically significant difference in the incidence of postoperative complications between the observation group and the control group （P > 0.05）. Conclusion The preservation of the mitral valve subvalvular structure and mitral membrane replacement surgery improved patient cardiac function， while there was no significant difference in mitral valve orifice blood flow parameters and complications compared with surgery without preservation of the mitral valve subvalvular structure.