The invention discloses a water-based polyurethane functional coating material and a preparation method thereof. The coating material comprises the following basic ingredients by weight percent: 10 to 40 percent of water-based polyurethane matrix resin, 1 to 10 percent of water-soluble acrylic acid resin, 1 to 5 percent of nano carbon material, 0.1 to 5 percent of silica sol, 0.5 to 2 percent of dispersing agent, 0.1 to 5 percent of moisturizing agent, 0.1 to 5 percent of leveling agent, 1 to 20 percent of butyl cellosolve, 0.1 to 10 percent of normal butanol, 0.1 to 10 percent of ethanol and the balance of water. By adopting the water-based coating material, the high-volume content addition of the nano carbon material can be realized, the conductivity and heat conduction performance of the coating can be effectively controlled, and high heat conduction performance and high conductivity characteristics can be obtained. The volatilization rate of solvent is reasonably controlled by virtue of flexible mixing, different construction coating process requirements can be met, and the applicability is wide. The novel functional coating material formula system can be used as a conducting coating material (ink), a radiation heat radiation coating material, an electric thermal coating material (ink), an antistatic coating material and an electromagnetic shielding coating material and has an important commercial value.