The invention discloses an automatic cleaning finish for exterior walls, and a preparation method thereof. The finish comprises, by weight, 30-60 parts of water, 0.1-0.5 parts of an antifoaming agent, 0.4-1.2 parts of an
antifreeze agent, 30-60 parts of an
emulsion, 0.8-2.0 parts of a film forming assistant, 0.1-0.4 parts of an
antiseptic and 0.01-0.5 parts of an
antistatic agent. The preparation method comprises the following steps: weighing above finish components according to above weight proportions; adding water to a finish preparation kettle; sequentially adding the
emulsion, the antifoaming agent, the
antifreeze agent and the film forming assistant while stirring; uniformly stirring above added components, and adding the
antiseptic and the
antistatic agent; and stirring above obtained components until uniformity to obtain the finished finish. The finish has exterior wall protection and decoration effects, has the advantages of excellent
stain resistance, weatherability, low
surface energy, high antistatic property and high light
transmittance, can realize automatic cleaning of building exterior walls by using wind and rainwater in
natural environment, solves the problems of easy
pollution, easy
efflorescence, color change and spalling of surfaces of buildings, and prolongs the service life of building exterior wall coatings.