Abstract: Seaweed polysaccharides have good physicochemical properties, such as moisture retention, gelation, film formation, thickening and stability, as well as biological activities, such as antioxidant activity, bacteriostasis, immune regulation, anti-tumor, anti-inflammatory, anti-aging, hypoglycemic and lipid lowering, which are widely used in the food industry. In this paper, the extraction, separation and purification of seaweed polysaccharides, as well as their applications in drinks, food packaging, meat products, confectionery and bakery products are reviewed, so as to make some contributions to food production and processing.