<p>This study aims to examine the impact of pre-existing fractures on the mechanical response of silty mudstone. A series of laboratory-scale triaxial compression tests were conducted on both intact and fractured rock specimens with varying fracture angles (<i>θ</i>) and connectivity ratios (<i>k</i>), corresponding mechanical properties, energy evolution, and failure mode were comprehensively analyzed under varying loading rates and confining pressure (<i>σ</i>₃). Results demonstrated that increased loading rates enhanced peak strength and elastic modulus, transitioning from ductile to brittle behavior, accompanied by shear-to-composite failure. Higher <i>σ</i>₃ extended the plastic deformation and effectively improved the structural strength and stiffness, although peak strength sensitivity decreases at higher <i>σ</i>₃. Fractured specimens exhibited reduced strength and stiffness compared to intact specimens, primarily attributed to cohesion loss rather than changes in internal friction angle. However, increasing <i>σ</i>₃ effectively mitigated fracture-induced mechanical degradation. The energy evolution of rock specimens indicates that total energy density (TED), elastic energy density (EED), and dissipated energy density (DED) exhibit distinct variations governed by <i>σ</i>₃, <i>θ</i>, and <i>k</i>, and the presence of fractures have a certain influence on energy accumulation and dissipation behavior, as reflected by decreased EED and increased DED associated with crack propagation. Furthermore, larger <i>θ</i> promoted tensile-dominated failure, while increased <i>k</i> exacerbated localized stress concentrations and intensified microcrack interactions, transitioning failure from combined tension-shear to tensile mechanisms, both of which provoked more severe damage in rock specimens. The results found in this study offer a reference for the further examination of fractured rock and numerical model calibration.</p>