Three ” pressing coal mining problem has become one of the increasingly prominent problem, therefore the filling mining technology has become the more important way to solve the “three ” pressing coal at present because of its function of control the strata movement, restricting the surface settlement. In the filling mining technology, backfill deformation situation can directly reflect the effect of filling. The coal gangue is a kind of granular materials, so there is no fixed parameters to describe the mechanical properties. Through a series of compacted test and the research of deformation of filling materials under a compression situation we can understand the backfill deformation, master the constitutive relation of filling coal gangue with compaction process. The result can provide a theoretical basis for study on the filling body''s deformation characteristics. At the same time, it can provide the basis for the selection of gradation for filling coal gangue, It is useful for selection and design for the transportation and processing equipments..