Abstract: Sea cucumber polysaccharide is a kind of active substance with unique structure and wide biological activity. Sea cucumber polysaccharide can be used as an immunomodulator or improve the health of the body by regulating the intestinal flora after entering the body. This paper summarized the classification and structure of sea cucumber polysaccharide, and comparatively analyzed the molecular weight, chemical composition, proportion of monosaccharide composition and sulfate content of different types of glycosaminoglycans and fucan sulfate. It also sorted out the effective mechanism of sea cucumber polysaccharide in controlling thrombosis through anti-thrombotic and anti-tumor cells by immunomodulation. Moreover, it reviewed the relevant progress of sea cucumber polysaccharides as prebiotics in regulating intestinal flora and improving metabolic diseases. It is important to elucidate the feasibility of sea cucumber polysaccharide as an effective active substance to improve blood clots, tumors, obesity, prospects for the development of sea cucumber polysaccharides in pharmaceutical and food research and development. diabetes and other health problems, providing a theoretical basis for the functional application of sea cucumber polysaccharide.