<p>Rock strength plays a key role in controlling fracture propagation and the stability of rock masses. However, how rock mass strength influences its internal deformation and fracture process remains poorly understood. This study investigates the effect of compressive strength on the damage evolution and instability mechanisms of rock-like models containing fractures. By combining failure stages and stress percentage, acoustic emission (AE) technology, strain blocks, and digital image correlation (DIC) technology were employed to analyze the signal characteristics of acoustic emissions prior to model instability, as well as the internal and surface deformation characteristics of the models and their interrelationships. The experimental results indicate that the acoustic emission signals generally exhibit a high–low–high trend during loading. The models with lower compressive strength demonstrate a more uniform distribution of signals over time and release less acoustic emission energy. Before global instability occurs,&#xa0;the local deformation at the prefabricated fracture was faster than the global deformation before the model reached global instability. Additionally, significant growth in internal deformation is observed prior to model instability, and the deformation characteristics inside and outside the model generally exhibit a certain functional relationship.</p>