The invention discloses a nontoxic environmental-protection building decorative material which is composed of the following ingredients, by weight, 2-3 parts of maleic anhydride, 5-10 parts of a film-forming additive, 1-3 parts of microlite, 3-4 parts of a phosphite antioxidant, 10 parts of a carboxylic styrene butadiene emulsion, 2-5 parts of open-cell expanded perlite, 4-8 parts of zinc oxide, 1-3 parts of silicon oxide, 8-11 parts of polypropylene, 5-10 parts of BAPTA, 10-14 parts of natural latex, 10-20 parts of a fire retardant, 3-6 parts of an anti-aging agent, 1-3 parts of glycerol triglycerate and 5-20 parts of a cosolvent. The invention has the following beneficial effect: microlite powder, an organic filler and the like are used as main raw materials, and the prepared building decorative material contains no chemical toxic or harmful substances, is environmentally-friendly and is simple to operate and convenient to construct.