Foreign various commercial serial softwares possess some disadvantages, such as the limited applicability, small-scale computing capacity and low efficiency. To overcome these disadvantages, we developed StrataKing (a GPU parallel computing system of strata motion) based on the hybrid Lagrangian-discrete element method in the past more than ten years. In this paper, the flow chart, basic principle and main features were introduced. Each computing modules were executed on GPU. The validation of StrataKing was conducted by modeling the cracking process of the three-point bending beam. Under the hydrostatic pressure, for finer meshes, cracks in the vicinity of the tunnel are more curved and gentle, extending toward the depth. The phenomenon is different from of the ring plastic zone in which failure occurs everywhere in plastic mechanics. During excavation, the peaks of the abutment and horizontal pressures were presented. The latter is related to the cohesion between strata, which is different from the radical stress of the thick-wall tube based on the continuous assumption. Thus, the large-scale computing capacity, wide applicability and apparent mining characteristics of StrataKing were further demonstrated.