Objective To investigate the effectiveness of perforator propeller flap of lower limb in the treatment of foot and ankle defect in children. Methods The clinical data of 28 children with foot and ankle defect treated with perforator propeller flap of lower limb between January 2018 and January 2021 were retrospectively analyzed. There were 18 boys and 10 girls with an average age of 7.3 years (range, 6-14 years). There were 8 cases of traffic accident injury and 20 cases of chronic infection wound. The disease duration was 2-4 months, with an average of 2.8 months. After thorough debridement, the residual wound size ranged from 5 cm×4 cm to 9 cm×5 cm. Repairing was performed after 7-28 days of the infection in control. According to the location, size, and shape of the wound, the perforating vessels were located by ultrasonic Doppler, and the perforator propeller flap (area ranged from 6 cm×5 cm to 11 cm×6 cm) was designed and harvested to repair the wound. Flap transfer combined with free split-thickness skin graft covered the wound in 2 cases. The donor site was sutured directly (22 cases) or repaired with skin graft (6 cases). Results Twenty-six flaps survived, of which 20 cases were in primary healing, and 6 cases had epidermal necrosis at the end of small paddle, which healed after dressing change. Necrosis occurred in 2 cases due to venous crisis which healed after anterolateral femoral flap free transplantation. Primary wound healing was achieved in donor site. All 28 children were followed up 6-24 months (mean, 10.5 months). The texture, shape, and motor function of the lower limb was satisfactory. At last follow-up, the American Orthopaedic Foot and Ankle Association (AOFAS) score was 89.8±8.0, which was significantly different from the preoperative score (79.6±10.4) (t=−11.205, P<0.001); 20 cases were excellent, 6 cases were good, and 2 cases were poor, and the excellent and good rate was 92.8%. ConclusionThe perforator propeller flap of lower limb in children has its own characteristics. It is a reliable method to repair the foot and ankle defect in children.