Employing an integrated methodology of theoretical analysis, numerical simulation, and coupled monitoring, this study conducted a systematic investigation into the deformation and instability mechanism of surrounding rock in gob-side entry driving under hard roof conditions, using the 21407 longwall panel of a specific coal mine as its research background. A mechanical structure model for the entry with a hard immediate roof under static-dynamic coupling loads was established to analyze the impact of both the gob-side cantilever beam structure and the hard arc triangular zone structure at the panel end on surrounding rock deformation. An innovative three-dimensional surrounding rock monitoring technology system was developed, which utilizes 3D laser scanning for dynamic deformation capture and integrates distributed bolt (cable) stress monitoring to form a coupled "deformation-stress" monitoring system, enabling a quantitative analysis of the full-lifecycle deformation laws of the surrounding rock. The results demonstrate that the surrounding rock is significantly influenced not only by the static load from the gob-side cantilever beam but also by the dynamic pressure originating from the hanging roof at the working face end. The deformation exhibits spatiotemporal evolution characteristics across five distinct phases: the driving influence period, stable creep period, long-term rheological period, mining influence period, and strong disturbance influence period. Integration of theoretical analysis and CDEM numerical simulation results revealed the deformation and instability laws, indicating a positive correlation between floor heave and roof subsidence, greater deformation on the small coal pillar side compared to the solid coal side, and a periodic pattern of asymmetric and alternately evolving deformation on both sides. The superimposed effect of static and dynamic loads forms a synergistic force source system, providing novel perspectives and ideas for innovating the deformation theory of surrounding rock in such conditions and offering a more scientific basis for determining optimal support timing.