An example according to the present invention provides a method of electrostatically coating nanoparticles at high speed including: a step S100 of preparing a dispersion solution including the nanoparticles charged with a charge opposite to that of a substrate; a step S200 of adding acid for increasing a proton concentration of the dispersion solution; a step S300 of coating the nanoparticles on the substrate; and a step S400 of removing a solution of the coated substrate.