Abstract: [Objective] To explore the possibility of application of navigation template based on reverse engineering in DDH osteotomy. [Method] Nine patients with unilateral DDH diagnosed and treated in the department of orthopedics of the fourth affiliated hospital of Harbin medical university from January 2017 to June 2019 were selected as subjects.Ages 2 to 8.There were 7 females and 2 males.There were 6 cases on the left and 3 cases on the right.According to Crowe, there were 2 cases of type II, 2 cases of type III and 5 cases of type IV.The affected hip joint was the experimental group and the healthy hip joint was the normal control group.The pelvis and bilateral femur of each patient were scanned by CT before surgery, and the DICOM data were imported into Mimics17.0 software for 3d reconstruction. Modified Pemberton osteotomy and proximal rotation/valgus osteotomy were simulated with reference to the anatomical parameters of the healthy side.The information of external surface and osteotomy plane of acetabulum and proximal femur were extracted postoperatively.Then the navigation template was applied to the 1:1 ratio 3D printed pelvic and femoral models of DDH children to perform modified Pemberton osteotomy and proximal rotation/valgus osteotomy, respectively. The indexes including acetabular index, femoral neck stem Angle and rake Angle were statistically analyzed in each group after surgery.[Results] There were statistically significant differences in acetabular index and rake Angle between the experimental group and the control group.There was no statistical significance among all groups. [Conclusion] Modified Pemberton osteotomy and proximal femoral rotation/varus osteotomy with individual acetabular and proximal femoral osteotomy navigation template and rotary navigation template can achieve accurate osteotomy of periacetabulum and proximal femur, providing the possibility for personalized surgical treatment of DDH.