<p>The adhesion strength of glaciers to underlying bedrock is a key factor controlling their stability on steep slopes or cliffs. In this study, a novel centrifugal testing method was developed for measuring ice–bedrock adhesion strength. A series of tests on ice–granite specimens reveals a linear relationship between adhesion strength and ambient temperature. In contrast, the effect of interfacial roughness follows a nonlinear pattern: adhesion strength increases with roughness at lower values but stabilizes or even decreases beyond a specific threshold. Based on the experimental data, a predictive model for ice–granite interface strength was established, providing a practical tool for evaluating glacier–bedrock adhesion. Furthermore, to enable simulation of the ice detachment process, the proposed ice–rock interface strength model was implemented into the PFC3D code. In this numerical framework, the flat joint contact model was adopted, and a quantitative relationship was first established between the micro contact strength parameters and both temperature and interface roughness. This relationship was then programmed in Python and embedded into PFC3D. For validation, a hypothetical mountain–glacier model was constructed to simulate the glacier failure process. The glacier’s stability response to temperature changes was quantitatively evaluated using the factor of safety. This demonstration confirms that the enhanced code can effectively simulate the progression of glacier instability. Our research advances the understanding of glacier–bedrock mechanical behavior and provides a practical approach for assessing glacier stability in high–mountain regions.</p>