The properties of silicon carbide waste produced from the recycled cutting slurry waste of solar-grade silicon were investigated.And the effect of silicon carbide waste on the mechanical properties of mortars was also examined.XRD, SEM and TG-DSC analyses were conducted to evaluate the effect of silicon carbide waste on the hydration of cement.The results showed that the major ingredients of silicon carbide waste are silicon carbide and silicon, while the content of SiC is different.Mortars incorporating silicon carbide waste exhibited lower mechanical properties than the reference before 7 days but the higher later.The active ingredients of silicon carbide waste, such as Si, reacted with Ca(OH)2, the hydration products of cement ,which promoted the further hydration of cement.