Gracilaria/Gracilariopsis lemaneiformis is an ecologically and economically valuable seaweed that has attracted attention for its unique flavour and rich nutritional content. Studies have shown that G. lemaneiformis contains a variety of chemical components, among which G. lemaneiformis polysaccharides (GLPs) are the main active components. GLPs are a class of biomolecules with significant pharmacological activities, which exhibit a variety of bioactivities in vitro and in vivo, including anti-inflammatory, immunomodulatory, regulating lipid metabolism, anti-oxidant, anti-allergic, and anti-cancer activity. Despite the great potential value of GLPs, their current research and review are still relatively limited, which hinders their development and utilization to some extent. Therefore, this study aims to systematically summaries the latest information on GLPs, covering extraction and purification methods, structural characterization, biological activities and conformational relationships. In addition, the potential applications of GLPs and related bibliometrics will be analyzed to provide basic data and references for future studies. In conclusion, this study will contribute to an in-depth understanding of the properties of GLPs and provide a strong scientific basis and direct reference for their more scientific and rational applications.