The invention relates to a composite silicate high viscosity hot and cold smear insulation slurry, which is prepared by the following materials mixed with water and comprises: expanded perlite 4 to 9 percent by weight, diatomite 2.8 to 6 percent by weight, hill cork 1.2 to 2.6 percent by weight, bentonite 3 to 6.5 percent by weight, alumina fiber 1 to 2.5 percent by weight, glass fiber 1 to 2.5 percent by weight, alumino-silicate fiber 1 to 2.5 percent by weight, vermiculite 0.5 to 1.3 percent by weight, polyvinyl alcohol 1.2 to 2.6 percent by weight, sodium silicate solution 0 to 0.2 percent by weight, and marginal water. The slurry is compounded by the above components, the inner part of the material forms a plurality of closed micropores, and the density is reduced obviously; the micropores are filled with static air having weaker heat conductive property, which can restrain the transmission of external heat effectively. The composite silicate high viscosity hot and cold smear insulation slurry has the advantages of light weight, low thermal conductivity, obvious heat preservation, insulation and deafening effect, high tensile strength, water and oil resistance, wide applied temperature scope and high bond force.