Abstract: Aiming at the problems of high risk of damage in physical core preservation, low efficiency and insufficient accuracy of traditional 3D modeling in water conservancy and hydropower projects, and in combination with the needs of the industry's digital transformation, this study takes the tens of thousands of meters of geological cores from the Three Gorges Water Hub Project as the research object. It has developed an improved core image acquisition device, integrated close-range photogrammetry technology, and constructed a full-process standardized operation system of "cleaning-fixing-automated shooting-aerial triangulation calculation-3D modeling". Multiple sets of comparative tests show that: compared with traditional manual shooting, the efficiency of single-group core shooting and preliminary processing with the improved device is increased by 50%, and the modeling success rate is increased from 75% to 96%; the constructed 1:1 3D real-scene digital model has a mean diameter error of 0.3396 cm and a mean length error of 0.1084 cm, which significantly improves issues such as texture discontinuities and detail loss, and can clearly restore characteristics such as fractures and mineral particles on the core surface. This research realizes the systematic upgrade of cores from "physical preservation" to "digital assets", provides a replicable digital management solution for water conservancy and hydropower projects, and helps the industry transform to a "digital-driven" model.