Microcosmic-to-macroscopic shale reservoir rock elastic mechanical property solving method

The invention relates to a cross-scale method for solving shale reservoir rock elastic mechanical parameters from microcosmic to macroscopic. The method comprises the following steps: 1, analyzing main mineral components of shale; 2, establishing a molecular model; 3, selecting a proper force field; 4, mechanical verification; 5, solving and verifying micro-mechanical properties of each mineral; 6, analyzing the lithology of a certain shale reservoir; 7, establishing a rock representative volume element model; 8, building a rock representative volume element attribute model; 9, carrying out grid division; 10, setting periodic boundary conditions; 11, applying a compression load; 12, solving and verifying macromechanical properties of different lithologic rocks of the shale reservoir; 13, macroscopic mechanical properties of different lithology rocks of the shale reservoir are compared and analyzed. According to the method, the mechanical properties of different minerals can be calculated, and finally the macr