The invention discloses water-based paint which has high heat dissipation and is applied to a wooden door. The water-based paint is prepared from, in parts by weight, 50-70 parts of a main material, 1-2 parts of C9 petroleum resin, 0.1-0.2 part of a catalyst, 1-2 parts of a water-based curing agent, 0.2-0.8 part of cocamidopropyl betaine, 0.4-0.6 part of octylphenol polyoxyethylene ether, 1-4 parts of a composite flame retardant, 2-8 parts of illite, 3-5 parts of quartz sand, 1-4 parts of diatomaceous earth, 1-2 parts of heavy calcium carbonate, 2-8 parts of coal gangue powder, 1-4 parts of hollow glass microbeads, 1-3 parts of an anti-settling agent, 1-3 parts of a dispersant, 0.5-2 parts of a leveling agent and 1-2 parts of a defoamer. A coating of the water-based paint has strong adhesion, a full paint film, no yellowing and brittleness, no organic solvent, a good thermal dissipation effect, excellent flame-retardant performance, superior comprehensive performance and a good protection effect on the wooden door, no peeling emerges on the surface after long-term use of the wooden door, and fire can also be prevented effectively when a fire occurs.