This　study　assessed　the　impact　of　calcium　silicate　slag　(CSS),　an　industrial　by-product　of　aluminum　extraction　from　fly　ash,　on　the　reaction　kinetics,　compressive　strength,　and　efflorescence　of　one-part　sodium　carbonateactivated　slag　(SCS).　Various　proportions　of　CSS　(0%,　10%,　and　20%)　were　used　to　substitute　for　slag.　The　resulting　performances　were　evaluated　through　chemical　shrinkage,　heat　liberation,　compressive　strength,　water　absorption,　phase　composition　(XRD　and　TG.),　microstructures　(BET　and　BSE-EDS),　and　simulated　efflorescence　test　(partially　and　fully　immersed　in　deionized　water).　The　results　indicate　that　the　CSS　possesses　a　porous　structure.　The　addition　of　CSS　impairs　flowability　but　accelerates　the　development　of　chemical　shrinkage　and　heat　liberation.　The　incorporation　of　CSS　promotes　the　transformation　of　gaylussite,　leading　to　an　increase　in　CASH　and　hydrotalcite　formation.　Consequently,　a　higher　compressive　strength　and　a　lower　water　adsorption　rate　are　achieved.　10%　CSS　addition　improves　the　splitting　tensile　strength　of　SCS　under　conditions　of　partial　immersion　in　the　efflorescence　test.　However,　a　20%　CSS　substitution　exacerbates　the　formation　of　efflorescence　products　and　reduces　the　splitting　tensile　strength.　These　observations　are　associated　with　residual　alkalis　in　CSS,　a　lower　Al/Si　ratio　of　products,　and　an　increase　in　capillary　pores　attributed　to　CSS　particles.　This　paper　demonstrates　the　feasibility　of　using　alkaline　solid　waste　for　slag　substitution　and　performance　regulation　in　SCS　and　reveals　the　underlying　mechanism.　The　prepared　CSS-SCS　binder　exhibits　much　lower　energy　consumption　and　CO　2　emission　than　traditional　cement-based　material,　as　determined　by　life　cycle　assessment.