[Objective] To investigate the short-term clinical effect of femoral lengthening biological stem half-hip replacement combined with large or small rotor reduction wire loop reconstruction in the treatment of unstable intertrochanteric fracture of the femur in the elderly. [Methods] Thirty patients with unstable intertrochanteric fractures of the senile femur were treated by WangnerSL double-action head and half hip replacement with biological extension stem in the Second Affiliated Hospital of Bengbu Medical College from June 2018 to July 2021. The operative time, intraoperative blood loss, postoperative complications, and so on were recorded. VAS and hip Harris scores were used before surgery and 3 and 12 months after surgery. Hip radiographs were reviewed 1 week, 3, 6, 12, and 18 months after surgery to observe whether the prostheses were loose or sinking, and hip function was assessed. [Results] All the operations were completed in this group. The average follow-up time was (12.5±6.5) months. Hip joints were stable after surgery, and no complications such as infection, dislocation, and loosening occurred. The Harris score rate was 83.3%, and the VAS score and Harris score showed a significant statistical difference. [Conclusion] In the treatment of unstable intertrochanteric fracture of the elderly femur, femoral lengthening biological stem half-hip replacement combined with large or small rotor reduction wire ligation can shorten the bedtime of patients, promote the functional recovery of hip earlier, reduce the occurrence of bed complications, the clinical efficacy is satisfactory, and has good clinical application value.