Tumor cells leads to enhanced glucose uptake and the conversion of a larger fraction of pyruvate into lactate even under the circumstance of abundant oxygen. This phenomenon of aerobic glycolysis is known as the Warburg effect. Lactic acid, as an important tool for tumor cells to modify the tumor microenvironment, promotes the process of tumor invasion and metastasis, and contributes to tumor development by inducing and recruiting immunosuppression-related cells and molecules. Lactic acid could efflux out of the cancer cells via the monocarboxylate transporters to prevent intracellular acidification. Lactate can inhibit the cytolytic activity of T cells and natural killer (NK) cells, promoting the differentiation of tolerogenic interleukin 10 (IL-10)-producing dendritic cells. Moreover, the lactate-derived lactylation of histone lysine residues can promote macrophage polarization toward the M2-like phenotype, suppressing the immune response within the tumor microenvironment. In this review, we discuss the role of lactate as an immunosuppressor molecule that contributes to tumor evasion from the aspects of lactic acid metabolism and its effect on immune cells. And we explore the possibility of targeting potential targets in lactate metabolism for tumor treatment. At last, we proposed a tumor immunotherapy strategy by inhibiting the pathway of aerobic glycolysis and proteins associated with the production and transport of lactic acid.