To address the challenges of poor stability in drilling chambers and complex development processes associated with vertical long-hole blasting in deep mining at the Ashele Copper Mine, the downward fan-shaped deep-hole blasting technique was proposed, with a focus on the influence of charging structures on blasting outcomes. Based on the dynamic Mohr-Coulomb strength criterion and the dynamic maximum tensile stress criterion, the radii of the crushed and fractured zones under different charging structures were calculated. With blasting fragmentation as the engineering control objective, the 1.8 m explosive -1 m air interval and 2 m explosive -1 m air interval schemes were identified as optimal. Numerical simulation demonstrates that under a hole layout with a hole bottom spacing of 3.6 m and row spacing of 3 m, these two charging structures achieve crack densities of 32.39% and 37.25%, respectively, significantly outperforming the comparative scheme by effectively enhancing rock fragmentation and reducing the risk of oversized fragments. Industrial trials show uniform blasting fragmentation, with an oversize fragment rate of 6.52% and a fines rate of 1.73%, meeting production requirements. The research results validate the rationality and feasibility of the optimized charging structure, providing a technical reference for efficient ore caving in similar deep metal mines.