The invention belongs to the field of latex paint and especially relates to a matte latex paint and a preparation method thereof. The matte latex paint includes, by weight, 10-20 parts of a synthetic resin emulsion, 10-30 parts of heavy calcium being 500-1000 meshes, 5-20 parts of needle-like wollastonite being 1500-2500 meshes, and 25-50 parts of water. By means of addition of the heavy calcium being 500-1000 meshes and the needle-like wollastonite being 1500-2500 meshes, more uneven surfaces are generated in a film microstructure formed from the latex paint on a surface of a material, thereby effectively generating light scattering and further significantly reducing side angle glossiness of the latex paint. A test result proves that the latex paint is lower than 5 degrees in 85-degree side angle light chroma.