Abstract: Seaweed polysaccharides are important active substance in seaweed,and their content is high. A lot of studies have shown that seaweed polysaccharides have good gel property,stability and film-forming properties,as well as biological activities like antivirus,anticoagulant,anti-tumor,immune regulation,antioxidant and so on. They are widely used in food,health medicine industry and cosmetics industry and so on. In this paper,the recent advances in the extraction,separation and purification of seaweed polysaccharides and their application were reviewed,and the advantages and disadvantages of different methods of extraction,separation and purification methods of polysaccharides were analyzed respectively. The application of seaweed polysaccharides in food,health care industry and cosmetics industry and so on were described in this paper. Some problems in the development of seaweed polysaccharides were pointed out,and the future development and application of seaweed polysaccharides were carried out with a view to the development of seaweed polysaccharides to make the development and utilization of seaweed polysaccharides improved and make seaweed polysaccharides industry promote sustained and healthy development.