Objective To compare the clinical outcomes of the partial latissimus dorsi musculocutaneous （pLD-MC） flap and the lateral thoracic artery perforator （LTAP） flap in volume replacement breast-conserving surgery. Methods A total of 49 patients who underwent volume replacement breast-conserving surgery in the Department of Breast Surgery at the Affiliated Tumor Hospital of Guangxi Medical University between July 2020 and July 2024 were included in this study. Based on the type of flap used， the patients were divided into an LTAP group （n=29） and a pLD-MC group （n=20）. Postoperative complication rates， operative time， and BREAST-Q scores were compared between the two groups. Disease-free survival （DFS） and overall survival （OS） was analyzed using the Log-rank test. Results The operative time in the LTAP group was significantly shorter than that in the pLD-MC group （P < 0.05）. Postoperative BREAST-Q scores showed that the LTAP group achieved significantly higher scores in physical well-being and satisfaction with surgical outcomes compared to the pLD-MC group （P < 0.05）. The complication rate was 3.4% （1/29） in the LTAP group and 10.0% （2/20） in the pLD-MC group， with no statistically significant difference between the two groups （P > 0.05）. Analysis of DFS and OS also revealed no statistically significant differences between the groups （P > 0.05）. Conclusion For tumors located in the outer quadrant of the breast， when the lateral thoracic artery perforator is anatomically identifiable and the lateral chest wall can provide sufficient tissue volume， the LTAP flap is associated with a shorter operative time and superior physical well-being scores postoperatively， while maintaining comparable safety profiles to the pLD-MC flap. Therefore， the LTAP flap may be considered the preferred option for volume replacement in breast-conserving surgery.