The invention provides a heat-insulation cooling type water-based mixed paint and a preparation method thereof. The heat-insulation cooling type water-based mixed paint is prepared from the followingraw materials in parts by weight: 50-60 parts of heat-insulating acrylic emulsion, 3-8 parts of polyvinyl acetate emulsion, 15-20 parts of micron-sized titanium dioxide, 3-5 parts of superfine bariumsulfate, 1-3 parts of wet sericite powder, 2-3 parts of a dispersing agent, 0.2-0.6 part of a defoaming agent, 1-1.5 parts of a flash-rust inhibitor, 0.1-0.2 part of a pH regulator, 0.2-0.5 part of abase material wetting agent, 1.5-3 parts of dipropylene glycol butyl ether, 1.5-3 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 1-2 parts of propylene glycol, 0.5-0.9 part of a shaking auxiliary agent and 2-5 parts of water; wherein the particle size of the micron-sized titanium dioxide is 1.58 [mu]m. The heat-insulation cooling type water-based mixed paint has the advantages of good heat-insulating and cooling effects, low VOC, environmental friendliness and the like, is suitable for the surface of an outdoor metal material, and plays a role in protection and cooling.