Abstract: The tailings and slag based mine filling cementitious materials was prepared by sodium silicate and sodium hydroxide alkali-activated tailings and slag.Through the test that the cementing materials in the best ratio of raw materials:when slag and tailings admixture is 1.25,the content of NaOH was 50%,the amount of sodium hydroxide for 50%,water cement ratio of 0.22,under the condition of normal temperature curing 7 days,eventually making a compressive strength of 52.3MPa cementing materials.