<p>Open-pit mines have abundant water resources. With deepening mineral extraction, groundwater increasingly impacts mine rock strength. Water critically controls ore strength, due to the substantial variation in water content at different locations within the mining area, this study investigates the blasting damage mechanisms of iron ore under three moisture conditions (dry, natural, and saturated states, with moisture contents of 0%, 0.33%, and 1.67%, respectively). Using hematite as the test subject, CT scanning and three-dimensional reconstruction techniques were employed to analyze the three-dimensional fractal dimension and damage extent of the blast-induced fracture fields in ore specimens under different moisture conditions. The results indicate that as the moisture condition of the ore transitions from dry to natural to saturated, the damage extent initially increases and then decreases, with the maximum damage occurring in the natural state and the minimum in the saturated state, showing an overall reduction of 6.55%. In the dry and natural states, the blasting damage extent is primarily influenced by the lubricating effect of water on crack initiation. In the saturated state, the damage extent is governed by the combined effects of the Stefan effect and the Meniscus effect, leading to a 30% reduction in main cracks and a complete elimination of branch cracks (100% reduction), along with smaller crack apertures compared to the natural state. This study concludes that blasting damage in ore is highly sensitive to changes in moisture state rather than directly correlated with moisture content. Even a 1–2% change in moisture content can significantly alter the damage extent under blasting loads if the moisture state transitions occur. These findings provide a theoretical and practical basis for designing blasting parameters in water-rich environments of open-pit metal mines.</p>