Abstract: To reveal the influence of dissolution pores on the mechanical properties of limestone in karst slopes, uniaxial compression tests combined with digital image correlation (DIC) were conducted to systematically investigate the coupled effects of pore number (1～4) and aperture (6～18 mm) on the mechanical response, strength degradation, and failure modes of limestone. The results show that: (1) peak strength, elastic modulus, and peak strain decrease significantly as pore number or aperture increases. The maximum reduction in peak strength reaches 62.55%, and the mechanical parameters show negative linear or exponential correlations with pore parameters. Three-dimensional nonlinear surface fitting was used to establish attenuation models for the mechanical parameters, accurately revealing the coupled attenuation effect of pore number and aperture. (2) Failure cracks appear successively as tensile cracks above and below the circular holes, lateral compression-shear cracks, and far-field cracks. With increasing pore parameters, tensile and compression-shear cracks become increasingly dominant, whereas the contribution of far-field cracks weakens. (3) DIC analysis reveals the strain-field evolution: strain is uniform during initial compaction; strain localization appears around the pores in the elastic stage; tensile cracking during crack propagation is controlled by stress concentration around the pores; and penetrating tensile failure or diagonal shear failure develops in the failure stage. The pore-rock damage constitutive model and crack-propagation criteria established in this study provide a theoretical basis for engineering rock-mass stability evaluation and geological-hazard prevention in karst areas.