Abstract: To explore the variation patterns of starch quality in chestnuts during short-term storage, three cultivars—Dabanhong, Laoshuli, and Yanshan Zaofeng—were selected for investigation. The physicochemical and structural properties of starch were analyzed after storage at −2 ± 0.5  ℃ and 90%~95% relative humidity. After 63 days, total starch content decreased by 6.13%~15.44%, while rapidly digestible starch declined by 34.82%~43.44%. In contrast, amylose content increased by 5.37%~19.54%, and resistant starch rose by 1.04 to 3.23 times, indicating enhanced starch resistance and reduced digestibility. In terms of thermal properties, the gelatinization peak temperatures of Dabanhong and Laoshuli starches increased by 2.38% and 2.45%, respectively, while Yanshan Zaofeng starch exhibited a higher gelatinization temperature and a 23.72% increase in enthalpy, suggesting superior thermal stability. Structurally, the starch granule morphology remained unchanged, whereas both short-range molecular order and relative crystallinity increased, indicating structural reorganization induced by storage. From a processing perspective, chestnuts stored for approximately 14 days showed higher sweetness, making them suitable for chestnut paste and ready-to-eat products; those stored for 63 days, enriched in resistant starch, are ideal for developing low-glycemic index functional foods. This study elucidates the regulatory role of storage in modulating chestnut starch structure and digestibility, providing theoretical support and practical guidance for optimizing postharvest processing timing and functional product development.