The application of Masquele technique in the repair of giant bone defects in adults has become more and more mature. Because of the great demand for autologous bone source in the second stage intramembranous bone grafting, it is considered that children and the elderly as the lack of autogenous bone source are relatively taboo people for the application of this technique. In this paper, a case of infective bone defect of femur in children was treated with Masquele technique combined with autologous bone marrow mesenchymal stem cell transplantation during 2020. On the premise of the failure of bone transport therapy, bone marrow was extracted from the ilium and BMSCs was enriched in allogeneic bone particles by bone growth negative pressure concentrator. In the first stage, antibiotic bone cement occupied space to control infection, and in the second stage, the bone defect was repaired by enriching autogenous BMSCs instead of autogenous bone and internal fixation with steel plate to complete the treatment of open fracture GustiloIIIB complicated with type IV chronic osteomyelitis without autologous bone, which achieved early exposure and avoided excessive treatment cycle of lower limb muscle atrophy and decline of motor function.