Polygonatum sibiricum, valued both as a medicinal and nutritional plant, has long been recognized for its health benefits. Increasing evidence highlights its polysaccharides (PSPs) as key components. As research into the structural characteristics and biological activity of PSPs continues to grow, there is rising interest in developing functional foods that harness their therapeutic potential. However, existing studies on PSPs remain fragmented, lacking a comprehensive framework for their application in functional food development and drug delivery. This review aims to fill that gap by systematically summarizing the purification, structural characterization, and diverse biological activities of PSPs. We also explore the significant potential of these polysaccharides in functional food development and their promising applications as natural, eco-friendly drug carriers. Furthermore, we address the key challenges and limitations in this field, offering insights into future research trends and opportunities for advancing PSPs in areas such as sustainable materials, functional foods, and therapeutic innovations.