Objective:To investigate the clinical effect of a segmented perforator flap of free peroneal artery to repair a complex defect after oral cancer. Methods:Forty-eight patients with oral cancer admitted to the Department of Oral and Maxillofacial Surgery of the First Affiliated Hospital of Bengbu Medical College from January 2018 to January 2022, including 8 of buccal cancer, 7 of floor cancer, 14 of tongue cancer, 5 of retromolar cancet, 9 of maxillary gingival cancer and 5 of mandibular gingival cancer. After lesion resection, 24 patients in the experimental group used the partial perforator flap to repair the defect, and 24 patients in the control group used the single flap to repair the defect. Compared with the general data of the two groups, the difference was not statistically significant(P>0.05), which was comparable. The flap cutting range of the experimental group was 38.5-74.5 cm², and tension-reduced suture for the donor area. In the control group, the myocutaneous flap incision range was 61.0-76.5 cm², and skin graft suture for the donor area. Flap survival and patient survival were recorded and compared. The patients were followed up at 6 and 12 months after surgery, and their swallowing function and speech function, including the drinking water test, functional oral food intake scale and the Chinese language clarity test word table, were evaluated respectively, and their subjective satisfaction with the repair appearance was recorded. Patients in both groups were followed up for 12 to 60 months. Kaplan-Meier method was used to calculate the cumulative survival rate of patients, and survival curves were plotted. log-rank test was used to compare the survival curves between groups. Results:The survival rate of the two groups was 100%. The 5-year survival rate was 62.5% in the experimental group and 54.2% in the control group. There was no significant difference between the two groups (P>0.05). According to the results of the functional recovery evaluation, the groups in swallowing and speech function and subjective satisfaction(P>0.05), and at 12 months after surgery(P<0.05). Conclusion:The segmented perforator flap of free peroneal artery is flexible and can repair different anatomical structures of postoperative composite defect of oral cancer, which can effectively improve postoperative functional recovery and patient satisfaction. Therefore, the peroneal artery segmented perforator flap is the ideal flap for reconstructing postoperative composite defect of oral cancer.