Objective: Given the disadvantages of a traditional heating method for preparing polysaccharide-iron, such as long producing time and low iron binding rate, the aim was to optimize the preparation technology of dark tea polysaccharide-iron (DTPIC-HP) under ultra-high static pressure and investigate its digestion characteristics in vitro. Methods: DTPIC-HP was prepared by ultra-high static pressure with black tea polysaccharide as material. The preparation conditions were optimized, and the stability and bioavailability in vitro were investigated. Results: The effects of pressure, the ratio of polysaccharide to iron and treatment time on the iron content in DTPIC-HP were non-linear, and quadratic and interactive effects were also found. The influential order of the factors on the iron content was as follows: ratio of polysaccharide to iron > treatment time > pressure. The optimized processing conditions were mass ratio of polysaccharide to iron of 1.7∶1.0, pressure of 425 MPa and treatment time of 22 min. Under the control of these conditions, the iron content in DTPIC-HP was 16.78%. The gastric and intestinal simulated digestion in vitro showed that the stability of DTPIC-HP was higher than FeSO₄, and its soluble iron content was 86.82% at the end of digestion. Conclusion: Ultra-high static pressure exhibited high efficiency for producing DTPIC-HP, which had good potential bioavailability.