The invention discloses an acid-proof 
cathode electrophoretic paint as well as a preparation method and an application method. The electrophoretic paint comprises 
emulsion and color paste, wherein the 
emulsion is prepared by steps of mixing amine modified 
epoxy resin, a totally-closed 
isocyanate cross-linking agent and an emulsifying agent, uniformly stirring at the temperature of 43 DEG C to 47 DEG C, adding 
formic acid at the temperature of 45 DEG C to 49 DEG C to perform an acidification reaction for more than 70 minutes, subsequently adding deionized water, uniformly stirring and then filtering. The color paste is prepared by the steps of mixing 
quaternary ammonium dispersion resin, deionized water, dibutyl 
tin oxide, kaolin, 
carbon black, an emulsifying agent, 
rutile titanium dioxide and 
titanium-based nanometer paste, uniformly stirring at the temperature not higher than 30 DEG C, 
grinding the mixture at the temperature not higher than 35 DEG C by use of a grinder until the 
fineness is not larger than 15 microns, uniformly stirring and filtering. An application process comprises batching, preparation of a tank and an electrophoretic 
coating process; the preparation of the tank comprises steps of mixing 10-15 parts by weight of the color paste, 35-40 parts by weight of the 
emulsion and 50-75 parts by weight of the deionized water, and curing for 48-50 hours at the temperature of 28-30 DEG C; and the electrophoretic 
coating process comprises a step of performing 
electrophoresis to a to-be-coated element for 3-4 minutes under the 
voltage of 200V.