Abstract: Existing inorganic thermal insulation materials in market has low thermal conductivity，heat preservation performance is poor，therefore，using metakaolin as the main raw material，sodium silicate as alkali excitation agent，aquae hydrogenii dioxidi as foaming agent，through polymerization preparation new exterior wall thermal insulation material.Influence of dosage of sodium silicate，dosage of foaming agent and curing temperature on the thermal insulation material density，compressive strength and coefficient of thermal conductivity were investigated.Results show that when mass ratio of sodium silicate to metakaolin is 1.0，aquae hydrogenii dioxidi dosage of 2% mass of metakaolin，curing temperature was 60 ℃，the thermal insulation materials coefficient of thermal conductivity is 0.115 W/(m ℃)，density of 356 kg/m3，the compressive strength of 0.821 MPa.Experimental results can provide technical support for preparation of exterior wall thermal insulation material using metakaolin.

Key words: Thermal insulation material, Metakaolin, Geopolymerization