The invention discloses environmental-friendly wallpaper capable of purifying air and a preparation method thereof and relates to the technical field of wallpaper. The environmental-friendly wallpapercomprises a base layer, wherein an air purification layer and a moisture-proof layer are respectively arranged on two sides of the base layer; the air purification layer comprises the following raw materials in parts: 45-55 parts of modified organic fibers, 25-35 parts of diatomite, 15-20 parts of essential oil components, 10-15 parts of bamboo vinegar, 10-15 parts of negative-ion natural mineralpowder, 4-6 parts of a thickening agent, 4-6 parts of a water-retaining agent, 1-3 parts of a plasticizer and 1-3 parts of an antifoaming agent; the moisture-proof layer comprises the following raw materials in parts: 55-65 parts of allyl benzene, 24-26 parts of nanoparticles, 10-12 parts of a surfactant, 5-10 parts of a bactericide, 5-10 parts of functional waterproof assistants and 4-6 parts ofsodium carbonate. The environmental-friendly wallpaper disclosed by the invention is environmental-friendly, safe and non-toxic, and indoor air can be effectively purified.