Abstract: Objective To explore the clinical effect of free transplantation of thoracodorsal artery perforator flap in reconstructing large scar on the facial subunit. Methods From April 2014 to March 2018, 7 patients with large facial scar were admitted to Ningbo NO.6 Hospital, including 3 males and 4 females, aged from 31 to 49 years, 4 with frontal involvement and 3 with chin and neck. Color Doppler ultrasound was used for the positioning of the thoracodorsal artery perforating vessel, and scar resection was performed according to the principle of facial subunit repair. The wound area was 8 cm×6 cm-21 cm×8 cm, and the wound was repaired with the free thoracodorsal artery perforator flap in the area of 9 cm×7 cm-22 cm×9 cm. The donor site was closed directly by suturing. The consistency of the location of the perforating vessel explored during the operation with its preoperative positioning and the flap survival were recorded. The color, texture, and appearance of the flap and the healing condition, scar formation, and function of the donor area were observed during follow-up. Results The locations of the perforating vessels of 7 patients explored during the operation were consistent with those positioned by color Doppler ultrasound before the operation. All the flaps of the 7 cases survived successfully after operation. Postoperative follow-up of 12-18 months showed that the flap color was similar to the surrounding skin of the recipient area, with soft texture and no obvious contracture. Slight bloated appearance was observed in the flaps of 4 cases. All the 7 patients had postoperative healing of the flap donor site without obvious scar hyperplasia or influence on shoulder joint function. Conclusions The anatomy of the perforating vessel of the thoracodorsal artery perforator flap is relatively constant and the flap can be cut in large area with soft texture, good appearance, and concealed donor area, which is a good choice for reconstructing large scar on the facial subunit.