Objective To study the stress distribution of the cartilage around the hip joint in the stress environment of the complete gait cycle, and to explore the best correction angle of the bone block in the curved periacetabular osteotomy (CPO), so as to provide a theoretical basis for clinical operation. Methods Based on CT scans of a healthy volunteer and a patient with development dysplasia of hip (DDH), the three-dimensional model including pelvis and proximal femur was reconstructed. Material attributes were assigned to the 3D finite element model by the method of Mask. To simulate CPO with DDH model, and 100 different postoperative models were obtained by rotating osteotomy. According to the stress of hip joint in the complete gait cycle, the model was loaded respectively, and the stress changes of normal, preoperative and postoperative of the acetabular cartilage were analyzed and compared. Results The minimum contact stresses of acetabular cartilage of DDH patient after simulated CPO operation in the whole gait cycle at five time phases were 5.273Mpa、6.128Mpa、7.463Mpa、6.347Mpa、6.582Mpa, which were 2.159 MPa, 2.724 MPa, 2.249 MPa, 2.164 MPa and 2.119 MPa less than those before operation, respectively. The contact area between femoral head and acetabulum was significantly increased after operation, but it was still smaller than that of normal volunteers. Conclusion The best correction angle of LCEA and ACEA can be obtained by using finite element method, and it is of great significance to simulate CPO surgery for different patients to improve surgical accuracy and efficiency.