Ophiopogon japonicus (O. japonicus) has a history of thousands of years as herbal medicine and nutritional food in China. Polysaccharides are one of the main bioactive components of O. japonicus. Various extraction methods and purification techniques have been employed to obtain O. japonicus polysaccharides (OJPs). Nevertheless, the structural characteristics of OJPs remain incompletely understood and require further investigation through the integration of advanced analytical techniques to uncover potential structure-activity relationships. Moreover, OJPs exhibit a variety of biological activities, such as regulating gut microbiota, providing cardiovascular protection, lowering blood glucose, and combating obesity. These diverse pharmacological effects make OJPs highly promising for widespread application in industries such as pharmaceuticals and food. Therefore, this review aims to provide a comprehensive overview of OJPs, covering their preparation methods, structural features, bioactivity, and structure-activity relationships. Here also emphasizes the significant promise of medicine and functional foods fields and advocating for their integration into clinical and industrial processes.