Objective To investigate the effect of ball milling treatment on the structure, physicochemical properties, and digestibility of high-amylose corn starch (HACS).Methods In this paper, the effect of different ball milling durations on the particle size distribution, microstructure, crystalline structure, short-range ordered structure, thermodynamic properties, and digestibility of HACS were analyzed.Results After ball milling treatment, starch granules were disrupted, the surface became rough, and agglomeration occurred, resulting in an increase in particle size. With prolonged milling time, the crystallinity of starch decreased from 21.02% to 0.03%, and the "Maltese cross" pattern gradually weakened and eventually disappeared. The amylose content increased from 71.435% to 79.285%, and the short-range order was enhanced. In terms of thermodynamic properties, the thermal stability of starch decreased after ball milling. In terms of digestibility, ball milling significantly improved the digestibility of HACS.Conclusion Frozen ball milling treatment can improve the physicochemical properties and enhance the digestibility of HACS.