Abstract: In order to alleviate the impact of surface soil scarcity on ecological restoration in high-altitude cold mining areas，whether the iron tailings to municipal sludge proportioning can be used as substitute material for surface soil was studied. The physical and chemical properties of surface soil substitute materials after mixing different types of iron tailings with municipal sludge and planting vegetation on surface soil substitute materials were studied. The test results show that it is feasible to use iron tailings and sludge as topsoil substitute materials. The organic matter content of the topsoil substitute material mixed with iron tail⁃ ings A and sludge is 2.42%~15.60%，and the soil bulk density is 1.07~1.49 g/m3，which meets the requirements of soil fertility organic matter greater than 0.5% and soil bulk density less than 1.50 g/m3 of "Land Reclamation Quality Control Standard"（TD/T1036-2013）. When the iron tailings A and sludge were mixed at a volume ratio of 9∶1，it had the best effect as a topsoil substitute material，with more plant vegetation survival species，higher plant growth height and survival rate.

Key words: organic matter, soil bulk density, iron tailings