Objective To explore the clinical efficacy of minimally invasive osteotomy, precise bone grafting combined with intramedullary nail dynamic treatment for delayed union and nonunion of bone after interlocking intramedullary nailing. Methods From January 2009 to October 2017, 21 patients with delayed union and nonunion of femoral shaft fractures were treated with minimally invasive autogenous iliac bone extraction, precise bone grafting combined with intramedullary nailing dynamization. Incision length, wound healing, postoperative complications, and fracture healing and knee function were observed. Results The incision was 1~2cm, and all incision healed at first stage. Fifteen patients were followed up for 12 to 24 months with an average of 16 months. Among them, 18 patients finally achieved radiographic evidence of solid union. and the healing rate was 90% without obvious complications. Conclusion Minimally invasive autogenous iliac bone extraction, precise bone grafting combined with intramedullary nailing dynamization is an effective method for the treatment of delayed union and nonunion. It has the advantages of less trauma, less complications, and economical and practical advantages.