Abstract: Regulatory T (Treg) cells are a class of immune cells characterized with CD4⁺ that exert negative immunomodulatory effects. By inhibiting the activity of effector T cells, they maintain the balance of the body's adaptive immune system to prevent the occurrence of autoimmune diseases. Treg cells, the main components of the immunosuppressive tumor microenvironment, also inhibit the immune response of effector T cells in the local tumor immune microenvironment and promote immunosuppression and tumor cell immune evasion, thereby facilitating the malignant evolution of the tumor. Aimed at prompting the understanding of the immunosuppressive microenvironment of pancreatic cancer, this review will systematically summarize the functional mechanisms of Treg cells in immune microenvironment remodeling in pancreatic cancer and the latest developments in clinical translational research, which may provide a new strategy for immune regulation therapy.