In　recent　years,　researchers　across　various　fields　have　shown　a　keen　interest　in　the　exploitation　of　biocompatible　natural　polymer　materials,　especially　the　development　and　application　of　seaweed　polysaccharides.　Seaweed　polysaccharides　are　a　multi-component　mixture　composed　of　one　or　more　monosaccharides,　which　have　the　functions　of　being　anti-virus,　anti-tumor,　anti-mutation,　anti-radiation　and　enhancing　immunity.　These　biological　activities　allow　them　to　be　applied　in　various　controllable　and　sustained　anti-inflammatory　and　anticancer　drug　delivery　systems,　such　as　seaweed　polysaccharide-based　nanoparticles,　microspheres　and　gels,　etc.　This　review　summarizes　the　advantages　of　alginic　acid,　carrageenan　and　other　seaweed　polysaccharides,　and　focuses　on　their　application　in　gel　drug　delivery　systems　(such　as　nanogels,　microgels　and　hydrogels).　In　addition,　recent　literature　reports　and　applications　of　seaweed　polysaccharides　are　also　discussed.