Abstract: A new inorganic cementitious material with microporous structure was prepared by single low-temperature sintering process with fly ash，carbide slag，and desulfurization gypsum as raw materials and with adding a small amount of mineralizer，adhesive agent，and pore-forming agent and the material′s performances were also studied.Taking the optimized formula and under the conditions of pre-heat temperature 400 ℃，roasting temperature 1 220 ℃，and holding time 25 min， water absorption，apparent density，and 3 d compressive strength of the prepared microporous cementitious material were 2.10%，1.32 g/cm³，and 8.56 MPa，respectively.XRD analysis showed the main phases of synthesized material were calcium silicate and gehlenite.Using industrial waste slag as raw material as well as the combination of porosity and cementitious character made the microporous cementitious material can partially replace cement and lightweight aggregates（haydite） to prepare insulating mortar so that the purpose of environmental protection and energy saving could be realized.

Key words: microporous, cementitious material, orthogonal tests