Abstract: Combined static and dynamic loading is one of the primary triggers of rockbursts, while borehole destressing serves as a crucial measure for their prevention and control. To investigate the response characteristics of borehole destressing under combined advance abutment pressure and disturbance loads, this study employs theoretical analysis and laboratory experiments coupled with acoustic emission (AE) and digital image correlation (DIC) techniques. The research examines the effects of borehole diameter, disturbance amplitude, and incremental static load on the mechanical properties, energy release, and fracture evolution of the specimens. The results indicate that the borehole diameter significantly influences the mechanical response of specimens during combined static and dynamic destressing experiments. Specifically, when the borehole diameter increases to 12 mm, the peak strength decreases by up to 28.11%, the fatigue strain increment during the disturbance stage reaches 39.79%, and the failure mode transitions from pure tensile failure to tensile-mixed failure. This demonstrates that large-diameter boreholes effectively mitigate rockburst risks through stress transfer. Furthermore, the influences of disturbance amplitude and incremental static load are governed by the borehole diameter: for small diameters, the peak strength increases with disturbance amplitude but remains independent of the incremental static load; for large diameters, the peak strength initially increases and then decreases with disturbance amplitude, while continuously decreasing as the incremental static load increases. Therefore, in engineering practice, destressing borehole diameters should be rationally selected based on the specific combined static and dynamic loading conditions. Additionally, large borehole diameters and high disturbance amplitudes promote fracture development and energy release, thereby reducing the severity of failure. The AF-RA fracture classification method verified that borehole destressing can successfully induce shear failure. These findings provide experimental evidence for verifying the unloading mechanism under combined static and dynamic loading, offering a valuable reference for optimizing borehole destressing parameters.