Abstract: Iron tailings are rich in SiO2 and Al2O3，and have potential pozzolanic activity，but the ac⁃ tivity is low at room temperature，and its reactivity can be improved by mechanical activation or chemical ex⁃ citation. A new type of iron tailings-based gelling material was prepared by using iron tailings，cement clin⁃ ker，gypsum and slag powder as test materials. Through the orthogonal test to optimize the ratio，the optimal combination was determined to be 15% iron tailings，35% cement clinker，10% gypsum，slag powder is the residual (40%)，and water-binder ratio of 0.50. The verification test showed that the compressive strength of the specimens at 3，7，and 28 d was 3.12，7.70 and 13.94 MPa，respectively. Further freeze-thaw cycle and hydration durability tests were carried out. The results show that the cementitious material has good frost re⁃ sistance under standard curing conditions，but the strength loss is significant in low temperature environ⁃ ment. Under the condition of long-term water immersion，the strength of the test block is slightly improved， and the saturated water absorption rate is between 2.17% and 3.11%，showing good hydration stability. The research results provide technical support for the resource utilization of iron tailings and the development of green filling materials.

Key words: iron tailings, gelling material, orthogonal test, filling performance