Objective By comparing the accuracy of different multi-rigid-body models used for simulating walking process of elderly women, to explore the effect of walking speed on the load of knee joints based on the obtained optimal model. Methods In human motion simulation software ADAMS/LifeMOD, the individualized human body models with 19 (M1), 16 (M2) or 12 (M3) links and the corresponding grounds were established, respectively. Then, the dynamic simulation of gait based on 3 models was conducted in turn. Results By comparing the vertical ground reaction force (vGRF), the walking time, the lower extremity joint angles among 3 models, M2 was the most applicable model to reproduce the real performance of gait. When elderly woman fastened their walking speed, the peak values of vGRF, the knee joint torque and power peak were all increased significantly. Conclusions It is suggested that elderly women should do more training for their quadriceps to improve their walking behavior. The research findings also provide references for rehabilitation treatment of knee osteoarthritis patients in clinic.