The study of the dynamic interaction between adjoining rock and structure is important to decide the load of underground structure scientifically and to analyze the dynamic stability of adjoining rock.The rock characteristics are important factors. And it is difficult to study through prototype test because the blast loading is a destructive load. The nonlinear dynamic finite element procedure of ANSYS/LS-DYNA is applied and the fluid-solid coupling algorithm is selected to study with different spans and the detonating distances constantly changing. The result shows that the mechanics status of big-span is completely changed compared with that of the structure of small-span. And different laws of rock types for structures with different spans are obtained. The study shows that dynamic interaction is remarkable between large span structure and surrounding rock of remote explosion.