Objective:To investigate the clinical effect of free deep femoral artery third perforating flap repaired soft tissue loss after Pilon fracture surgery in I stage.Methods:Fifteen patients were treated from April, 2013 to January, 2020. Miller AO classification: 8 cases 43-C1, 4 cases 43-C2 and 3 cases 43-C3. All cases were accompanied with severe soft tissue contusion and skin necrosis. After fracture reduction, soft tissue defects, internal fixation exposure and tendon exposure around the wound. Free deep femoral artery third perforating flap (3.5 cm ×15.5 cm to 5.5 cm×12.5 cm) for the repair of soft tissue defects around ankle in the I stage, the blood vessels of the flap were end-to-side anastomosed with vessels of the posterior tibial or anterior tibial. Regular follow-up after surgery.Results:One case of venous crisis occurred, other 14 cases survived, were followed-up from 5 to 18 months, the ankle joint function was good, did not affect the foot shoes, with excellent color and texture, the flap restored protective sensation, and leaving only linear scar, no muscle adhesion.Conclusion:Free deep femoral artery third perforating flap repaired soft tissue loss of surgical incision after fracture operated than significantly reduce the postoperative fracture infection and protect the blood supply around the fracture. It is an effective method of repair.