Abstract: This study employed response surface methodology to optimize the preparation process of phosphorylated chicory polysaccharide iron. It characterized the structure of the composite using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Through simulated artificial gastrointestinal fluid digestion experiments, sucrase hydrolysis experiments, and mucin-binding capacity assays, the in vitro digestive characteristics of phosphorylated chicory polysaccharide iron were systematically analyzed. The results indicated that the optimal reaction conditions were a reaction time of 1.1 h, a reaction temperature of 64 ℃, and a pH of 10. Under these conditions, the iron content of the prepared phosphorylated chicory polysaccharide iron reached 26.97%±0.25%. Infrared spectroscopy of phosphorized chicory polysaccharide iron showed that the O-H and C=O groups in the phosphorized chicory polysaccharide coordinate with Fe³⁺. XPS confirmed that iron was introduced into the phosphorized polysaccharide in the trivalent state (Fe³⁺). SEM observation revealed that the composite morphology was a dense layered structure. In vitro gastrointestinal digestion results showed that the iron retention rate in gastric fluid was >97% after 24 hours, while in the simulated intestinal environment containing mucin and sucrase, 59% was released after 7 hours, with a cumulative release rate of 74.5%±0.5% after 24 hours. This study provides a theoretical basis for the high-value utilization of chicory polysaccharide resources and the development of polysaccharide iron supplements.