Objective To explore the effectiveness of one-stage debridement and two-stage Ilizarov bone transport technology in repairing post-traumatic lateral malleolus defect. Methods Between June 2013 and December 2016, 7 patients with bone defect of lateral malleolus were treated. There were 5 males and 2 females with an average age of 45.9 years (range, 35-60 years). There were 6 cases of traffic accident injury and 1 case of strangulation injury. All patients had extensive soft tissue injury and lateral malleolus bone exposure. There were 4 cases of Gustilo type ⅢB and 3 case of Gustilo type ⅢC. The time from injury to admission was 3-10 hours (mean, 6.3 hours). Through one-stage thorough debridement, exploration and repair of vessels and nerves, external fixation of scaffolds and coverage of wounds, free fibulas were removed in 3 cases at one-stage and fibulas were resected in 4 cases after expansion. The bone defects ranged from 4.5 to 15.0 cm in length (mean, 8.2 cm). The Ilizarov circular external fixators were used to transport with fibula osteotomy for repairing bone defect of lateral malleolus when the wound healing. Results During fibular osteotomy, the stents were adjusted 2-4 times (mean, 2.8 times) and the external fixators were removed after 10-16 months (mean, 12.8 months). The nail tract infection occurred in 2 cases during transporting and was controlled after symptomatic treatment. All patients were followed up 24-48 months (mean, 32.9 months). The shape of lateral malleolus was close to normal without obvious varus or valgus deformity. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind foot score was 86-92 (mean, 90.3), and 5 cases were excellent and 2 cases were good. X-ray film showed that there was no obvious widening of the gap between the ankle points and no sign of absorption of the lateral malleolus. Conclusion The one-stage debridement combined with two-stage Ilizarov bone transport technology can maintain the stability of ankle joint structure and obtain better effectiveness in repairing post-traumatic lateral malleolus defect.