Abstract: Primary liver cancer (liver cancer) is one of the main indications of liver transplantation. However, postoperative recurrence of liver cancer severely affects the long-term clinical efficacy of liver transplantation. Programmed cell death protein 1 (PD-1) is an immunosuppressive molecule. Activation of PD-1/programmed cell death protein-ligand 1 (PD-L1) signaling pathway plays a pivotal role in the immune tolerance of grafts. In recent years, immune checkpoint inhibitor(ICI), such as PD-1/PD-L1 inhibitor, has become one of the effective approaches to treat advanced liver cancer, whereas ICI can be applied in liver transplant recipients is highly controversial, and the efficacy and safety remain to be studied. In this article, the expression of PD-1/PD-L1 in liver allograft tissues, the mechanism of PD-1/PD-L1 inducing transplantation immune tolerance and clinical application of PD-1/PD-L1 inhibitor in liver transplantation for liver cancer were reviewed.