Abstract: Taking paste filling in Daizhuang coal mine of Zibo mining group as the study background，based on the physicochemical properties of gangue，fly ash etc，the uniform experiments concluded the optimal proportion of paste filling material.Then，studies on mechanical properties of paste are carried out which is maintained for 28 d，the contractive analysis on mechanical properties between paste and replacement coal is made.The results show that the filling materials have greater residual strength，a clear plastic strengthening characteristics under action of the ambient pressure.Meanwhile，the angle of internal friction and the binding coefficient of the paste material are gained.The plastic characteristic of the paste materials is more obvious than that of coal through the contrast tests with the mechanical properties of the replaced coal.

Key words: Coal waste paste, Physicochemical properties, Proportion experiment, Mechanical properties