Myeloid-derived suppressor cell (MDSC) mainly exists in tumor microenvironment (TME) and interferes with normal immune response of the body. These immature differentiated cells cooperate with tumor cells for immune escape and proliferation. The subtypes of MDSC are different in different organisms, and STAT become a high priority for the signaling pathway mediating the regulation of MDSC. The surface of MDSC cell population contains a variety of signal molecular receptors, and its differentiation degree is toilless to be chemotaxis by different factors. The role of MDSC in silencing T cells and promoting regulatory T cells (Treg) is particularly significant. This review mainly contains the origin of MDSC, the characteristics of subgroups, the focus of the study on MDSC heat molecules and signaling pathways, the relationship between MDSC and carcinoma, prognosis and hope to propose an overview of current MDSCs- targeting therapies so as to provide new ideas for cancer treatment.