The invention discloses acrylic acid outer wall latex paint and a preparation process thereof, relates to the technical field of paint, and solves the problems that due to the fact that an outer walllatex paint coating layer is easily aged under the effect of an external environment, the overall application effect of the outer wall latex paint is not good. The acrylic acid outer wall latex paintcomprises, by weight, 320-350 parts of water, 2-5 parts of hydroxyethyl cellulose, 8-12 parts of ethylene glycol, 1.2-1.6 parts of polydimethyl siloxane, 90-110 parts of titanium dioxide, 95-115 partsof kaolin, 4-5 parts of wollastonite powder, 260-280 parts of ground calcium carbonate, 170-190 parts of pure acrylic emulsion, 3-5 parts of Tex film-forming agent, 0.8-1 part of PT86 mildew preventive, 0.8-1.2 parts of neutralizer, 4.5-7.5 parts of dispersing agent and 1.2-2.4 parts of pitaya seed extract. The acrylic acid outer wall latex paint has the advantages that the coating layer after the acrylic acid outer wall latex paint is used is good in stability, the coating layer cannot be easily aged under the effect of the external environment, and the overall application effect of the acrylic acid outer wall latex paint is good.