Abstract: To investigate the dynamic mechanical behavior and damage evolution mechanisms of coal specimens containing boreholes under impact loading, this study employs a split Hopkinson pressure bar (SHPB) testing system in conjunction with a discrete-continuous coupling approach to conduct dynamic impact experiments and numerical simulations on coal specimens with different borehole diameters. Results show that, under high strain rate loading, the peak stress of coal specimens decreases monotonically with increasing borehole diameter, while post-peak stress drop slows and post-peak strain significantly extends. Owing to the wave-impedance effect induced by the borehole, the proportion of reflected energy increases, whereas the proportions of transmitted energy and dissipated energy decrease. In terms of failure mode, cracks in intact specimens initiate at the incident end and propagate along the stress wave direction, exhibiting tensile splitting failure; in contrast, strain concentration in specimens with boreholes first occurs around the hole periphery and then extends toward both ends, resulting in a transition to tensile-shear composite failure. The total number of cracks and fragments in the borehole-containing specimens decreases, the proportion of tensile cracks declines while that of shear cracks increases, and the fragment volume becomes larger. The numerical simulations capture the crack propagation trajectories and localized damage zones. It is observed that the fracture morphology transitions from a linear "I" pattern to a complex "X" network, resulting in a significant enlargement of the damage zone in the hole-containing coal samples. While elevated impact velocities facilitate damage propagation, increasing confining pressure effectively suppress this progression, characterized by a marked increase in the ratio of shear cracks.