The invention provides a latex coating material. The latex coating material contains the following ingredients in parts by weight: 24-38 parts of water, 0.27-0.36 part of sodium hexametahposphate, 0.03-0.04 part of soap, 1-2.3 parts of tributyl phosphate, 7-11 parts of talcum powder, 8-11 parts of calcium carbonate, 12-16 parts of titanium white and white carbon black with the particle size of 85-135nm, 0.15-0.25 part of sodium carboxymethyl cellulose, 3.5-5 parts of film forming assistant and 28-30 parts of styrene-acrylic emulsion, wherein the parts (by weight) of white carbon black with the particle size of 85-135nm are 18-28% the total parts (by weight) of titanium white, calcium carbonate, talcum powder and white carbon black with the particle size of 85-135nm, the film forming assistant is a mixture of glycol, 1,2-propanediol and F-974 film forming auxiliaries, and the parts (by weight) of 1,2-propanediol are 2.5-3.5. The invention further provides a preparation method of the latex coating material, wherein the method comprises the steps of dispersing and mixing various auxiliaries and the like. According to the latex coating material and the preparation method thereof, a styrene-acrylic emulsion coating material is improved by using white carbon black with the particle size of 85-135nm, so that the latex coating material which simultaneously has the advantages of low glossiness and high strength can be obtained.