The invention discloses a unicompartmental knee joint prosthesis and a manufacturing method thereof. The unicompartmental knee joint prosthesis comprises a femur condyle, a gasket and a tibial plateau, wherein a first porous structure is arranged on the inner surfaces, making contact with a host bone, of a femur connecting column and a femur condyle body, and a second porous structure is arrangedon the surfaces, making contact with the host bone, of a tibia connecting column and the tibial plateau body. The invention discloses a manufacturing method of the unicompartmental knee joint prosthesis. The manufacturing method comprises the steps of S1, additive manufacturing of a femur condyle, S2, hot isostatic pressing treatment of the femur condyle, S3, machining of the femur condyle, S4, additive manufacturing of a tibial plateau, S5, hot isostatic pressing treatment of the tibial plateau, S6, machining of the tibial plateau and S7, surface modification. According to the invention, theporous structure provides space for ingrowth of human bone tissue so as to improve stability of the prosthesis; the tibial plateau is endowed with a bioactive function through the in-situ membrane layer, so that bone induction and bone ingrowth of the tibial plateau can be rapidly achieved in the early stage of implantation; and the prosthesis is endowed with good mechanical properties through thehot isostatic pressing process, so that long-term safety and effectiveness of the prosthesis are facilitated.