The quality of backfill has great influence on the quality of mine filling,and settlement and compressive strength are the two physical and mechanical properties of backfill.In order to improve the filling capacity of the mine and meet the safety requirements of production in the Tuokuzibayi Gold Mine,the settlement mode of tailings,the various pulp concentrations and different ash-sand ratios of cementation filling are studied through experiments,so as to obtain the best settlement speed and meet the appropriate value for safety production during cementation filling.The results show that the natural settlement is difficult to make the clarified layer completely clarified,and the admixture of poly aluminum is better than the poly iron in aiding settlement.When the amount of aluminum is up to 1 000 g/t,the pulp concentration of the compression zone is 62.89 %,which can be completely clarified.For the onestep ore room filling slurry with high 3 d compressive strength,the ash-sand ratio should be 1∶4 or 1∶5.When the 3 d compressive strength is not high enough,the as-sand ratio can be down to 1∶8.In order to meet the 28 d compressive strength≥0.5 MPa,the two-step ore room should control the concentration of tailings pulp at 68 % to 72 %,the ashsand ratio is 1∶12,and the concentration of filling slurry is 70 % to 72 %.