3D printing is a new food processing technology with important application prospects，and is also a research hotspot in the field of food science． Based on the acquisition of starch gelatinization materials with different gelatinization degrees，this paper investigated the evolution behavior of multi-scale structure of rice，wheat and potato starch materials in the gelatinization control system and the influence of structural evolution on the molding properties of 3D printing through modern structural analysis technology． The results show that with the increase of gelatinization degree from 30% to 70% ，the layered structure of starch granules is destroyed gradually and the compactness of nano aggregates decreases significantly; relative crystallinity decreases continuously; the content of double helix and single helix decreases significantly and the proportion of amorphous structure increases significantly． Meanwhile，with the increase of starch gelatinization degree，the thread width of 3D printing decreases first and then increases，while the number of printing layers increases first and then decreases． The ideal printing molding properties can be achieved when the gelatinization degree of rice，wheat and potato starch materials is 50% ，40% and 30% ，respectively． The research results provide a certain data basis for the precise design and quality control of starch gelatinous materials and starch food．