Abstract: Investigating the dynamic response of the surrounding rock deformation to the height of the weak interlayer in the roof is of great significance for stability control and safe, efficient mining in deep gob-side entry driving. Based on physical and numerical simulation tests, this study analyzes the deformation and instability characteristics as well as the evolution laws of surrounding rock at different weak interlayer heights in gob-side entry driving. The influence mechanism of the weak interlayer height in the roof on the mechanical behavior of the surrounding rock is analyzed, and a mutual control support method for the roof and sidewalls at different weak interlayer heights is proposed. As the weak interlayer height decreases, the surrounding rock deformation gradually increases. The maximum deformation and principal strain concentration in the small coal pillar are greater than those in the solid coal, revealing asymmetric distribution characteristics. The critical stress—threshold where the monitored stress in the small coal pillar exceeds the applied model stress—increases from 3.0p to 5.0p (p denotes the original rock stress) as the weak interlayer height decreases from 70 mm to 10 mm, indicating a gradual reduction in the bearing capacity of the small coal pillar.With increasing model load, the weak interlayer in the roof undergoes three stages of separation: low-amplitude stability, ascending transition, and rapid acceleration. As the weak interlayer height decreases, the load threshold for the transition to the ascending stage decreases, and the maximum roof separation location shifts from the small coal pillar side to the solid coal side. Additionally, with a decrease in the weak interlayer height, the extent of roof shear and tensile fractures gradually increases, and the fracture zones connect to the weak interlayer separation area, leading to intensified surrounding rock deformation. The area of large-scale sidewall fractures also increases, showing clear asymmetric distribution characteristics, clarifying the effect of weak interlayer height on the deformation and instability of the surrounding rock in gob-side entry driving. A stability classification system for the surrounding rock in gob-side entry driving is established using the weak interlayer height in the roof as the key parameter. Based on the above classification, a mutual control support method for the roof and sidewalls is proposed for different stability levels, thereby establishing a theoretical foundation for controlling the surrounding rock in gob-side entry driving at various weak interlayer heights in the roof.