Objective To explore the effect of heart-shaped cosmetic suture technique on scar aesthetics in parturients undergoing repeat cesarean section with scarred uterus. Methods A total of 80 parturients undergoing repeat cesarean section with scarred uterus admitted to the Department of Obstetrics and Gynecology of our hospital from January 2022 to June 2024 were selected as the research subjects. According to the random number table method, they were divided into the control group and the observation group, with 40 parturients in each group. The control group received traditional interrupted suture technique, and the observation group received heart-shaped cosmetic suture technique. The operation-related indicators, scar aesthetics, complication rate and satisfaction were compared between the two groups. Results The suture time of the observation group was shorter than that of the control group (P <0.05). There was no statistically significant difference in intraoperative blood loss between the two groups (P >0.05). The VSS scores, scar width and thickness of the observation group at 1, 3 and 6 months after operation were lower than those of the control group (P <0.05). The incidence of complications in the observation group was 5.00%, which was lower than 22.50% in the control group (P <0.05). The satisfaction rate of the observation group was 92.50%, which was higher than 72.50% of the control group (P <0.05). Conclusion Heart-shaped cosmetic suture technique can effectively improve the incision healing quality of parturients undergoing repeat cesarean section with scarred uterus, reduce scar formation, with shorter suture time, lower risk of complications and higher patient satisfaction.