An artificial knee joint comprises a femoral condyle prosthesis and a tibial plateau prosthesis; wherein the tibial plateau prosthesis includes a medial tibial plateau prosthesis and a lateral tibial plateau prosthesis disposed at both sides of the tibial plateau intercondylar eminence, respectively. The artificial knee joint further comprises a locating pin for fixing the tibial plateau prosthesis. The bottom surface of the tibial plateau prosthesis is provided with a prosthetic notch, and the tibia below the tibial plateau prosthesis is provided with a tibial notch. The prosthetic notch corresponds to the 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.