Selenium is an essential trace element for life. It plays an irreplaceable role in delaying human aging, improving immunity, preventing cardiovascular diseases and treating Keshan disease. There are inorganic selenium and organic selenium in nature. Selenopolysaccharide plays an important role in the selection of selenium supplements, but the selenium content of selenopolysaccharide is generally low, so there are some regional limitations in obtaining selenopolysaccharide. In order to improve the biological activity of selenium polysaccharides, organic selenium polysaccharides with high selenium content have become one of the hot spots of research and development. Selenium polysaccharide has a variety of biological activities, such as anti-tumor, anti-virus, improving immunity and so on. The research status of selenium polysaccharide at home and abroad in recent years was reviewed, including the source, preparation and biological activity of selenium polysaccharide. The future development and utilization of selenium polysaccharides in the field of health care or medicine is of great significance.