Abstract: The plastic failure of strip-style goaf areas due to weathering, groundwater erosion, and overburden load is one of the main causes of geological disasters in the surrounding rocks of goaf areas. Revealing the stress evolution laws under the expansion of the coal pillar plastic zone is the theoretical foundation for achieving stability in strip-style goaf areas and protecting surface structures. This study, taking a specific strip-style goaf in a mine as the research background, employs a combined method of physical similarity simulation experiments and numerical calculations to study the deformation and failure characteristics of the goaf overburden during the expansion of the coal pillar plastic zone. This study reveals the spatiotemporal evolution laws of the gradual change in the magnitude and direction of mining-induced stress. The results indicate that as the plastic zone of the strip coal pillar expands, the height of the overburden and the surface subsidence values increase gradually, after the coal pillar is fractured, the failure area of the goaf roof is connected, leading to a significant increase in the range of overburden failure and the height of fracture development; influenced by this, the goaf area forms a symmetric arch-shaped stress transmission path along the middle of the goaf, stress concentration areas are formed at the coal pillars at the arch feet, and the range of these areas migrates inward with the expansion of the coal pillar plastic zone; the peak value of the first principal stress of the coal pillar shows an increasing trend, and the direction of the first principal stress of the coal pillar also deflects, with the deflection angle gradually increasing.