<p>To address the unclear variation patterns of three-dimensional mining-induced stress and the ambiguous relationship between different stress states and rock strength in deep mining, a comprehensive research methodology integrating theoretical analysis, numerical simulation, and field measurements was employed. This study investigated rock strata’s stress magnitude and direction evolution under single-sided goaf conditions. The influence mechanism of principal stress deflection on surrounding rock instability under high-stress excavation unloading was revealed. The results show that as the working face advances, abutment pressure undergoes a dynamic evolution: stability, growth, and subsequent attenuation, exhibiting spatial zoning demarcated by the peak influence. Excavation triggers significant stress rotation in rock strata, altering the loading–unloading state and driving complex three-dimensional stress path evolution involving magnitude and direction changes. Ahead of the coal wall, principal stress initially increases and decreases, with the maximum principal stress exhibiting the most significant increase and rotating toward the horizontal plane. In different disturbance zones, the principal stress follows an initial increase to subsequent decrease stress path, with the stress variation amplitude diminishing from the intense disturbance to the stable zone. With higher rock strata elevation, stress variation amplitude and rotation angle decrease influenced by adjacent goaf. The discrimination index of three-dimensional stress disturbance intensity is proposed, and the stress evolution paths dominated by rock load, fracture orientation, and the combined control of fractures and rock load are clarified. These provide a theoretical foundation for stability control under the combined influence of stress magnitude and loading direction.</p>