The invention provides a formaldehyde removal coating and a preparation method thereof, and relates to the field of formaldehyde treatment. The formaldehyde removal coating comprises the following components in parts by weight: 5-10 parts of an activated carbon loaded nano TiO2 material, 3-5 parts of chitosan, 3-5 parts of rosin resin, 0.1-1 part of nano graphene, 5-10 parts of lignin, 1-5 parts of a plant extract, 1-5 parts of light calcium, 0.2-2 parts of biological enzyme, 30-50 parts of silicone acrylic emulsion, 0.05-1 part of a coalescing agent, 0.05-1 part of a defoaming agent, 0.05-1 part of a dispersing agent and 20-40 parts of water, the biological enzyme comprises peroxidase, formaldehyde dehydrogenase and polyphenol oxidase, wherein the plant extract is an aloe extract, a Chinese ivy extract, an Agave americana extract and a dayflower extract. Through use of the formaldehyde removal coating, formaldehyde is removed in a manner of combining physical adsorption, chemical catalysis, the biological enzyme and the plant extracts, the removal effect is improved, and the formaldehyde removal coating is safe, non-toxic and harmless.