Composite heat-insulation coating and preparation method thereof

The invention discloses a composite heat-insulation coating and a preparation method thereof, and belongs to the field of heat-insulation materials. The composite heat-insulation coating comprises the following components: 15-45% of rutile titanium dioxide, 15-30% of propyl acetate emulsion or phenyl acetate emulsion, 3-6% of silicon carbide, 3-7% of aluminum oxide, 1-6% of zinc oxide, 0.5-2% of a film-forming auxiliary agent, 0.5-2% of a de-foaming agent, 0.5-2% of a wet dispersant, 0.5-2% of an anti-freezing agent, 0.5-2% of a flatting agent and 25-45% of water, wherein the solid content of the propyl acetate emulsion or the phenyl acetate emulsion is greater than 45% and less than 55%; the lowest film forming temperature is 3-7 DEG C; the sizes of the rutile titanium dioxide, the silicon carbide, the aluminum oxide and the zinc oxide are less than 100 nanometers. The composite heat-insulation coating is simple in process and has good heat preservation and heat insulation, and brushing resistance.