Abstract: objective To establish a three-dimensional finite element model of knee joint with different knee bending angles of 3° and 7° in the single condyle replacement of tibial prosthesis, and to study the biomechanical characteristics of knee joint with two kinds of posterior dip Angle, prosthesis wear and its effect on function. Methods combined with the human knee joint CT and MRI image and the third generation of Oxford prosthesis, establish the tibia prosthesis after pour 3 ° and 7 ° bend your knees 0 °, 30 °, 60 °, 90 ° and 120 ° of the finite element model of single condyle replacement, on the center of the lateral femoral condyle 1000 n load simulation of the human body stance phase load, analysis of different order condyle prosthesis knee Angle and maximum stress and distribution of articular cartilage. Results knee knees five angles pour 3 ° and 7 ° after tibial prosthesis research shows that maximum stress five knees angles meniscus pad 3 °, respectively, compared with 7 ° increased 28.06%, 68.99%, 19.45%, 21.06%, 53.38%, the distribution area from the gasket side to concentrate in the central area, 120 ° bend your knees when obvious stress concentration, less value, this is because the meniscus liner contact with the end of the femoral prosthesis is akin to point contact cause; The maximum stress of the tibial prosthesis was concentrated in the medial side when it was tilted 3° backward. As the bending Angle increased, the stress spread from the root of the prosthesis to the surface. The angular contact of the shin prosthetics is tapered, decreasing at 0°, 30° and 60° at the knees and increasing at 90° and 120° at the knees. For the femoral and tibial cartilages, there are three readings of the readings at five knees. The contact stress of femoral cartilage was the largest at 0° and the smallest at 90°, with the difference of 113.76% and 10.22%, respectively. Conclusion single condyle prosthesis by stress varies with Angle, knee flexion Angle changes after tibial prosthesis and produce change, tibial prosthesis pour 3 ° single condyle prosthesis after maximum stress value not less than 7 °, the stress concentration area enlargement lead to wear and prosthetic loosening, the contact stress of articular cartilage and concentrated area then dip Angle increases, the high stress concentration is more obvious when the buckling Angle, articular cartilage of the larger the peak stress will lead to the happening of the lateral compartment osteoarthritis, the results can provide clinical knee joint replacement surgery single condyle provides the theory basis for the design.