Abstract: Based on the filling mining project of Gushan Mining Company,on the basis of existing filling materials,the ratio test is carried out through orthogonal design to measure the parameters of filling body,such as uniaxial compression strength,slump of filling slurry,bleeding rate and shrinkage rate.Multiple linear regression model was established based on SPSS and obtained the regression equations of each test index by fitting,and the influence rules of slurry concentration,slag powder content,cement-sand ratio on the performance indexes of backfill and slurry were obtained,and the priority order and influential degree of factors were determined.The test results show that the order of influence on the uniaxial compressive strength of the filling body 28 d is:cement-sand ratio>slurry concentration>slag powder content.The factors affecting the slump degree,bleeding rate and shrinkage rate of the filling slurry are:slurry concentration>cement-sand ratio>slag powder content.By conducting the F test,t test and regression diagnosis of the regression model,it is known that there is no collinearity between the concentration,the slag powder and the cement-sand ratio.As a whole,it has significant influence on the regression equation and the regression coefficient,and the multivariate linear regression equation has a good fitting effect.