Abstract: The in-situ stress field of shale reservoirs undergoes dynamic changes during hydraulic fracturing operations, potentially inducing wellbore and formation damage. These changes directly influence the orientation and extent of fracture network propagation, subsequently impacting the optimization of fracturing strategies and ultimate development efficiency. Conventional geology-engineering integration 3D static model cannot accurately capture the dynamic evolution of the in-situ stress field during hydraulic fracturing. To address this limitation, this study proposes a fully coupled 4D dynamic seepage-stress simulation workflow based on the finite difference method that integrates high-resolution 3D geomechanical model with shale bedding heterogeneity, geological mechanical characteristics, and the complexity of the fracture network propagation. The method simulates the entire process from the initial in-situ stress field to stress disturbance induced by pore pressure diffusion during fracturing under actual formation conditions, which offers a multi-dimensional and multi-scale analysis of the impact of horizontal well fracturing on regional in-situ stress. Results show that as hydraulic fractures initiate during the fracturing process, the fracturing fluid permeates into the formation through the fracture network around the wellbore, and the wellbore pressure propagates outward, resulting in an increase in pore pressure. Consequently, both effective stress and in-situ stress exhibit varying degrees of decline, with the minimum horizontal in-situ stress showing the greatest drop. As the pressure-affected zone expands, the near-wellbore zone exhibits the most concentrated changes in pore pressure and in-situ stress, resulting in stress concentration and a pressure-drop funnel relative to the undisturbed far-field formation, inducing formation deformation and compression that alter the orientation of the in-situ stress. The simulation method and research findings, which integrate high-resolution geological model with fully coupled finite element analysis to construct dynamic in-situ stress field for fractured reservoirs, provide new insights and references for optimizing shale reservoir fracturing operations.