[Objective] To observe the clinical effect of the treatment of genu valgus with femoral shortening by internal closed wedge osteotomy of distal femur and Orthofix unilateral external fixation. [Methods] From January 2014 to June 2018, 6 cases of genu valgus with femoral shortening were analyzed retrospectively. Full length films of both legs were took and the femurs were shortened from 3.50 to 8.00cm. The femoral-tibial angle, the lateral angle of distal femur and the movement range of knee joint were recorded before treatment. The operation for genu valgus with femoral shortening by internal closed wedge osteotomy of distal femur whit tomofix plate fixation and proximal femur osteotomy whit Orthofix unilateral external fixation. After the treatment, the length of femur extension, femoral-tibial angle, distal femur lateral angle, the movement range of knee joint, plate removal time, external fixation time and external fixation index were observed and recorded. The function of knee joint was evaluated by HSS score. [Results] The osteogenesis of the lengthened part of the femur was good, the lengthened length was from 3.00 to 7.00cm, the removal time of the external fixation bracket was from 14 to 21 months, the external fixation index was from 2.67 to 4.67 months/cm, the removal time of the steel plate was from 17 to 22 months with a follow-up of 4 to 12 months after the removal of the steel plate. At the last follow-up, the femoral-tibial angle and the lateral angle of distal femur of the affected limb increased significantly compared with those before operation, and the difference was statistically significant (P＜0.05). At the last follow-up, the movement range of knee joint of the affected limb did not change significantly compared with those before operation, and the difference was not statistically significant (P＞0.05). At the last follow-up, HSS score was from 86 to 98, excellent in 5 cases and good in 1 case. [Conclusion] Internal closed wedge osteotomy of distal femur combined with Orthofix single lateral external fixator can effectively treat genu valgus with femoral shortening, which is worthy of clinical promotion and application.