Abstract: Local mines with cemented filling mining method，the strength of the filling body is the direct factor that affects the stability of the underground mining，and it relates to the stability of Stope wall rock and filling cost，reasonable ratio of filling material is the key.Based on the laboratory filling test of this article，using numerical simulation methods on four kinds of cement-sand ratio of filling to fill mining simulation，analysis on the deformation characteristics of cemented filling，the results show that the failure of the fill is mainly from the bottom of it and which contact with the footwall，then the contact area and the footwall upwards along the filling body，and in the bottom interface tendency direction along the filling body，the two direction gradual deformation.Comparative analysis on mechanical response of surrounding rock，such as displacement，stress and plastic zone，et al，the results show that the filling body is able to maintain the stability of the stope and the filling material cost is lower，when the cement-sand ratio is 1：8.The research results have certain significance on mine-filling works.