The invention provides a polysaccharide compound extracted from sargassum, and belongs to the technical field of the extraction of polysaccharides. The extraction of a sargassum polysaccharide comprises the following steps of cell wall disruption, concentration and alcohol precipitation, protein removal and freeze drying, wherein the step of the cell wall disruption comprises the following sub-steps of taking and making sargassum powder into a sargassum solution, adding an active polypeptide, using a sodium phosphate buffer solution as an extracting agent, repeatedly freeze-thawing, treating by an ultrasonic wave, centrifuging, and taking a supernatant solution, so as to obtain a protein extracting solution. The polysaccharide compound from the sargassum, which is extracted by the invention, has excellent anti-oxidation and anti-tumor effects, and can be used in a health-care product and the extraction process of the polysaccharide compound from the sargassum is simple, high in operability and low in production cost.