The　aim　of　this　research　is　to　explore　the　feasibility　of　using　tailings　sand　(TS)　as　a　partial　replacement　for　sand　in　the　production　of　cement-stabilized　base　course　materials.　In　this　paper,　the　performance,　economic　and　environmental　benefits　of　cement-stabilized　tailings　sand-gravel　base　material　(CSTSM)　with　various　TS　content　were　comprehensively　studied.　The　results　indicate　that　the　mechanical　properties,　drying　shrinkage　strain　and　durability　of　CSTSM　decreased　with　the　increasing　TS　content　(0%-30%)　while　adhering　to　the　necessary　engineering　requirements　(UCS＞2.4　MPa).　The　TS　inclusion　reduces　hydration　product　coverage,　decreases　compactness　and　increases　porosity,　resulting　in　reduced　strength　and　durability　of　CSTSM.　When　the　TS　content　is　below　16%,　the　deterioration　in　mechanical　properties　and　durability　of　CSTSM　under　dry-wet,　freeze-thaw　and　sulfate　corrosion　conditions　is　relatively　minor,　sufficiently　meeting　with　the　heavy　traffic　demands　on　highway　subgrades　(UCS＞4　MPa).　Moreover,　when　compared　to　ordinary　cement-stabilized　base　course　materials,　the　use　of　TS　reduces　the　cost　and　CO2　emissions.　After　a　comprehensive　comparison　of　performance,　economic　benefits　and　environmental　factors,　a　16%　TS　substitution　ratio　is　recommended　for　achieving　optimal　outcomes.　Utilizing　CSTSM　in　subgrade　engineering　is　promising　and　environment-friendly　approach　for　large-scale　solid　waste　treatment　and　achieving　carbon　neutrality　goals.　©　2025　American　Society　of　Civil　Engineers.