Objective: to reduce injury under physiology load and provide guidance to knee joint recovery by research mechanical behavior of knee joint under physiology load. Methods: A 3D finite element model was established considering total knee joint with meniscus, cartilage and ligament, and numerical simulation was carried out under the condition of standing on two legs and one leg respectively by using CT scan images and 3d reconstruction software. Electrical logging experiment was carried out on artificial knee joint, and computing result and experimental result were contrasted. Results: Comparison between numerical simulation with artificial knee joint and experiment demonstrates calculation model established in this paper reflects mechanical behavior of knee joint under physiology load correctly. The load applied to knee joint when standing on one leg is greater than that of standing on two legs. The load of inner side of both knee joint cartilage and meniscus are relative large and they are easy to be worn. Contact stress of the inner edge of meniscus is relative large, leading the inner edge tend to be worn. Among contact stress, numerical order from large to small is meniscus, tibial cartilage and femur cartilage. When meniscus is injured, load transports mainly through articular cartilage. Conclusions: The results of numerical calculation and electrical logging experiment show total knee joint model with meniscus, articular cartilage and ligament can reflect mechanical behavior of knee joint under physiology load correctly. Meniscus plays an important role in bearing load within knee joint. Protecting meniscus from being injured is important to protect knee joint. There are significant meanings in protecting knee joint, and designing and optimizing biology instrument and prosthesis.