Despite the long-standing emphasis on the role of T lymphocytes in cancer immunosurveillance, initiatives to improve the effectiveness of antitumor immune responses have been stimulated by the recognition that tumors may evade the response of T cells. Current research progress in T-cell immunobiology contributed to overcoming tumor immune escape mechanisms. Because of the inhibition of T-cell regulatory type in cancer patients, immune checkpoint inhibitors have shown significant antitumor activity. In this paper, we systematically review the current research progress on immune checkpoint inhibitors in tumor therapy in recent years to improve the accuracy of immunotherapy.