To improve the pozzolanic activity of the pulverized powder from the high temperature sintering slag of surface treatment sludge and construction residue, the effect and mechanism of Ca(OH)2 on the mechanical properties, microstructure characteristics and heavy metal leaching behavior of cement-based materials with pulverized powder were studied. The results show that when Ca(OH)2 content is 0.8% of the total mass of cement-based material, the mechanical properties of cement-based material mixed with grinding powder are better. At 7d, 28d and 60d, the flexural strength increased by 23.5%, 9.3% and 7.8% compared with the blank group. Microscopic test results show that a small amount of Ca(OH)2 can not only increase the specific surface area of cement-based hardened slurry, but also increase the number of hydration products, and improve the structural compactness of hardened slurry. However, when the content of Ca(OH)2 exceeds 0.8% of the total mass of cement-based hardened slurry, it has a negative effect on the structure and properties of cement-based hardened slurry. It is also found that the addition of Ca(OH)2 can reduce the leaching concentration of harmful heavy metals in cement-based materials with the addition of ground powder. The leaching rates of Cu, Ni and Zn were 17.5%, 13% and 40.8% lower than those of blank group. It can ensure that the leaching values of harmful heavy metals Cu, Ni, Zn and Cr in cement-based materials mixed with grinding powder are lower than the leaching concentration limits specified in the Technical Specification for Cooperative Disposal of Solid Waste in Cement Kiln (GB30760-2014).