Abstract: In light of the tail mud disposal challenge caused by sand stone production by mine waste rock preparation machine,and taking into account the mined-out area filling treatment,the technical idea to dispose of tailing mud by filling is put forward.To obtain the ratio of filling slurry that meets the requirements of pipeline transportation,a slump test was carried out to test the fluidity of filling slurry and the slump of tailing mud (-0.352 mm) of different ratios and rice gravel(5～10 mm).The results show that when the tailing mud content is less than 50 %,the fine aggregate cannot completely fill the pores due to the rice gravel absence and large porosity,and it is easy to be isolated; when the tailing mud content is ≥50 %,rice gravel is suspended in a fine aggregate slurry,and the backfilling slurry has good workability,water retention,and cohesion,and the prepared backfilling slurry can meet the requirements of pipeline transportation.Slurry concentration fluctuation has a significant impact on the slump.