Abstract: Rock fracturing is crucial for hydrothermal fluid migration and metal enrichment, influencing the scale, shape, and spatial distribution of ore bodies. The mechanisms governing differences in fracture modes are controlled by multiple factors such as rock lithology, mechanical properties, and tectonic stress regimes. The mechanisms by which different factors lead to variations in fracture modes require quantitative constraints. Based on Anderson's fault theory and the modified Griffith criterion, this study systematically analyzes the control mechanisms of pore fluid factor (λ_v) and differential stress (σ₁-σ₃) on three types of fracture modes (extensional fractures, extensional-shear fractures, and shear fractures) for different lithologies (granite and slate) under various tectonic regimes (normal fault, reverse fault, and strike-slip fault) at different depths. At the same depth (4 km or 6 km), granite (with a ratio of tensile strength to cohesive strength of approximately 0.55-0.62) develops a complete sequence of all three fracture types under different tectonic regimes, whereas slate (with a ratio of tensile strength to cohesive strength of approximately 0.66-0.75) lacks extensional-shear fractures in all tectonic regimes. For normal faults, the increase in differential stress is relatively slow, with extensional fractures dominating at shallow depths, while shear fractures dominate at greater depths. For reverse faults, differential stress increases rapidly with depth, leading to a preference for shear fracturing. During the reactivation of rock fractures, shear fractures dominate at all depths. If subsequent fault healing occurs, shear fractures may develop. The calculation results indicate that, at the same depth, lithological differences are the primary factor controlling variations in fracture modes. Under the same tectonic regime, depth variations significantly influence rock fracture modes, while lithological differences have a minor effect. Differences in fracture modes between different tectonic regimes are more pronounced. For pre-existing fractures under varying conditions, reactivation due to changes in mechanical properties generally manifests as shear fractures. This study contributes to deepening the understanding of fracture dynamics theory in hydrothermal mineralization systems and provides a theoretical reference for target selection in deep hydrothermal mineral exploration.