Abstract: the evolution of mechanical response of coal and rock is the root cause of coal and rock disaster. It is of great sig-nificance for safe and efficient production of coal mine to clarify the evolution law of mechanical response of coal and rock in stope. Based on the engineering background of longwall fully mechanized mining face of a mine, this paper adopts the method of physical similarity simulation and numerical calculation to study the step change rule of static mechanical response of coal and rock under the influence of structural transient on the basis of comprehensively determining the distribution characteristics of abutment pressure before and after coal mining. The results show that the overlying rock spatial structure is composed of rock strata with different lithology outside the fracture plane and within the mining influence range, and is the internal cause of the different mechanical response of coal and rock in the mining influence range. During the compression period, along with the accumulation of quantitative changes in the progressive evolution of mechanical properties such as boundary conditions and geometric properties within the overlying rock spatial structure such as coal excavation, instantaneous instability of the sub-system of the overlying rock spatial structure such as hard rock breaking occurs during the compression period, and then transient mechanical properties of the overlying rock spatial structure occur. Under this influence, the mechanical response of coal and rock in the stope is transient, the peak abutment pressure decreases sharply, and the peak position transitions to the front of the working face, forming a positive and negative step change zone. Based on the instantaneous fracture characteristics of hard rock, a numerical simulation pre-treatment method for the instantaneous fracture of hard rock is established. By this method, the spatial structure of overburden rock and its mechanical response transients can be quantitatively studied.