T cells play an important role in antitumor immunity. Numbers and function of T cells are controlled by regulating the uptake and utilization of nutrients, and their antitumor activity can be promoted by targeting metabolic pathways. In this review, we highlight the relationship between metabolism and cellular function of T cells. Specifically, we emphasize the metabolic state of tumor-infiltrating T cells and review key pathways that affect the antitumor function of T cells. In the field of tumor immunotherapy, targeting T cell metabolism to enhance the immune response is a new therapeutic strategy for enhancing immunotherapy combined with traditional treatments.