<p>Non-penetrating hole defects, ubiquitous in both natural rock masses and engineering structures, critically influence overall stability and safety. In this study, uniaxial compression tests were performed to experimentally investigate the mechanical, acoustic emission (AE), and strain field responses of yellowish sandstone specimens containing a cylindrical hole with different depths. Numerical simulations were also conducted to examine the stress and crack evolution of the defected models. A linear reduction in the uniaxial compressive strength (UCS), elastic modulus, and peak strain was observed in response to increasing hole depth. The evolution of the AE characteristic parameters shows stage characteristics during the compression process. The significant fluctuation of b-value after the quiet period of damage is a precursor to rock instability and fracture. The larger the hole depth is, the more the b-value decreases. The energy release level of AE fracture points increases with their occurrence time, with later-occurring events corresponding to higher energy and primarily concentrating around the hole. The numerical simulation results demonstrate good agreement with the experimental data. The distribution of stress concentration and release coincides with the spatial distribution morphology of the cracks. The simulated crack propagation pattern is consistent with the experimental observations of AE activity and strain localization. Failure in both the defected specimens and their models is characterized by macroscopic diagonal shear. A distinct contrast is observed between the initial X-shaped and the final butterfly-shaped aggregation of cracks, strain, and AE events, corresponding to increased hole penetration. The results are valuable for enhancing the predictive capabilities regarding the stability of rock engineering containing defects, thereby informing safer design and risk mitigation strategies.</p>