Abstract: In order to understand the effect of different alcohol contents (30%~100%) on starch structure and physicochemical properties under ultra-high-pressure field (200, 400, 600Mpa), changes of starch multi-scale structure and physicochemical characteristics were investigated. Related techniques such as scanning electron microscopy, small-angle X-ray scattering, X-ray diffraction and rapid viscosity analysis were applied for evaluating how pressure fields and alcohol content affected the granular structure, lamellar structure, crystallinestructure, pasting and retrogradation behaviors of starch. Results showed that starch granular, lamellar and crystalline structures were severely disrupted under 600 MPa pressure and pure water solution, and the peak viscosity of starch gradually decreased. And the alterations from starch ordered structure to its disordered form were significantly inhibited with the increased alcohol content (30% to 100%), whereas its peak viscosity displayed an irregular trend. Furthermore, the alcohol content during ultra-high-pressure treatment can also significantly impeded the retrogradation behavior of starch, and the relative crystallinity of retrograded starch presented a strong positive correlation with the setback value of starch. Therefore, this research may provide theoretical guidance for rationally controlling the starch structure and functional properties based on ultra-high- pressure with different solution polarity.