[Objective] To investigate the efficacy of free thinned sensate anterolateral thigh perforator flap for repair of large soft tissue defect in the foot and ankle . [Methods] Nine patients underwent reconstruction of large soft-tissue defects in foot region with a thin innervated anterolateral thigh flap. Preoperative ultrasound-guided localization of the nerve and vessels. After debridement. First incise the inside of the flap, dissect the lateral femoral cutaneous nerve and perforating blood vessels, incise the lateral margin to complete the free, trim the fat to the thickness of the flap 5 mm to 8 mm. The sensory recovery of the flap was evaluated using a four-grid eight point method. The functional recovery of the flap was evaluated using AOFAS score. [Results] All the patients got flaps survived after operation . All patients were followed up for 10～60 months. At the last follow-up. The number of monofilamental tactile identification of flaps was significantly lower than the healthy side (p<0.001). The number of sharp-blunt discrimination significantly was lower than the healthy side (p<0.001). The recovery of touch perception and sharp-blunt discrimination in the center of the flap was better than that in the periphery (p<0.05).The AOFAS ankle-hindfoot score was significantly higher than preoperative points (p<0.001). The Vancouver Scar Scale score was [(4.78±1.48) points]. [Conclusion] For large soft tissue defect in the foot and ankle, the free thinned sensate anterolateral thigh perforator flap has the reliability of sensory restoration, the shape matches the opposite side, being able to walk painless with wearing ordinary shoes, as well as minimal donor site morbidity.