Abstract: Mix proportion experiments were conducted on early-strength composite filling materials by employing full tailings as the main raw material to enhance the early strength of mine backfill and reduce filling costs. The physical and chemical properties of the full tailings were analyzed, and the compatibility of four types of early-strength agents with full tailings paste was evaluated, with the mix proportions of composite cementitious materials optimized by orthogonal experiments. The results show that the HY-3 early-strength agent performs best in improving early strength, increasing the 3-day strength by approximately 50 % at a dosage of 1 %. Without activators, the synergistic effect of clinker and mineral powder significantly enhances later-stage strength. In the system containing activators, the c4 formulation （45 % clinker + 40 % mineral powder + 10 % quicklime + 5 % anhydrous sodium sulfate） achieves the 3-day, 7-day, and 28-day compressive strength of 2.06 MPa, 4.70 MPa, and 7.70 MPa respectively under the cement-sand ratio of 1∶6 and slurry concentration of 76 %. This meets the mine’s false bottom strength requirement and enables low-cost replacement of traditional cement-based filling materials. The results can provide reliable technical support for low-cost, high-strength, and high-efficiency mine filling.