Lithium residue is a solid waste generated in the production of lithium carbonate from zinnwaldite,typically rich in silicon dioxide,aluminum oxide,calcium oxide,and iron oxide.Moreover,lithium residue after calcination can produce a glassy phase,which is a potential precursor for preparing construction materials.By testing the physical and chemical property of lithium residue,experiments were designed to improve the filling ratio of lithium residue-cement using an activator.The compressive strength of the filling body at 7 d and 28 d was tested,and the mixture formula was optimized using Design-Expert software.The results show that the compressive strength of the optimized lithium residue filling body meets the filling requirements at 28 d,indicating its potential to substitute cement as underground filling and cementitious material,thus reducing filling costs and realizing the utilization of solid waste resources.