<p>Natural bioactive polysaccharides play a crucial role in human health, largely dependent on their digestion in the gastrointestinal tract. Given the complexity and individual variability of the human digestive system, in vitro gastrointestinal digestion models have become essential tools for assessing the digestive characteristics and bioavailability of polysaccharides. These models exhibit several advantages, including dynamic sampling, good reproducibility, and ease of operation. They are capable of accurately predicting the relationships between the composition, structure, and digestive characteristics of polysaccharides, while effectively assessing their impact on gastrointestinal health. Despite their limitations in fully replicating the complex digestive environment, these models provide valuable platforms for studying the effects of polysaccharide digestion and fermentation on human health. This review provides a comprehensive overview of the current status and applications of in vitro gastrointestinal digestion models, specifically examining the digestion kinetics, influencing factors, and biological effects of natural bioactive polysaccharides within these systems. It offers important insights for research on the health impacts of polysaccharides and suggests that future studies should aim to further optimize these models to enhance their application in biomedicine and functional foods.</p> Graphical Abstract <p></p>