The invention describes an artificial knee joint, which includes a femoral condyle prosthesis and a tibial plateau prosthesis, and said tibial plateau prosthesis includes a medial tibial plateau prosthesis and a lateral tibial plateau prosthesis respectively disposed at both sides of the tibial plateau intercondylar eminence. The artificial knee joint further includes a locating pin for fixing the tibial plateau prosthesis. The bottom surface of said tibial plateau prosthesis is provided with a prosthetic notch, and the tibia below said tibial plateau prosthesis is provided with a tibial notch. Said prosthetic notch corresponds to said tibial notch, together forming a limiting hole for accommodating the locating pin. The cooperation between the locating pin and the limiting hole can ensure relative position stability and balance between the medial tibial plateau prosthesis and the lateral tibial plateau prosthesis. Said tibial plateau prosthesis includes an upper gasket and a lower gasket, and the lower gasket is provided with an elastic subassembly, so that not only a shock absorption function but also a limiting fixation function can be achieved.