Objective The stress distribution of the lumbar spine L1–5, fibrous rings and nucleus pulposus of the patient in mid-phase of single-leg support under slow-walking gait was studied, to determine the optimal correction angle of the osteotomy block in curved periacetabular osteotomy (CPO), and provide an individualized plan for clinical surgery. Methods The femur-pelvis-lumbar spine DICOM data of a patient and a healthy volunteer were obtained using CT scanning to construct a three-dimensional finite element model. The cortical bone, cancellous bone, and a series of cartilages were delineated using the modeling software, and the model was analyzed by finite element method using simulation software. The patient’s lateral center edge angle (LCEA) and anterior center edge angle (ACEA) were 15°, and 16 different postoperative models (LCEA=15°,25°,35°,45°and ACEA=15°, 25°, 35°, 45°) were obtained by computer simulation of the surgical osteotomy process. The stress differences in the regions of interest of the model were compared and analyzed, which were also compared with those of patient before surgery and the healthy volunteer, so as to obtain the optimal surgical plan. Results The stresses applied to the lumbar spine decreased with increasing LCEA and ACEA angles, with the lowest stresses applied to the lumbar cones, nucleus pulposus, and annulus fibrosus in the LCEA=35°, ACEA=35°models; then, the stresses applied increased with increasing angles. Conclusions The optimal correction angle for LCEA and ACEA can be obtained using the finite element method, this method is of great significance to improve the accuracy and efficiency of CPO for different patients.