The invention discloses a preparation method of environment-friendly PP plastic. The environment-friendly PP plastic is prepared from the following components in parts by weight: 58 to 88 parts of PP resin, 5 to 19 parts of plant fiber starch, 8 to 16 parts of calcium carbonate, 1.3 to 3 parts of nano titanium dioxide, 6.8 to 9.8 parts of silane coupling agent, 1 to 2 parts of nano silver oxide, 8 to 12 parts of graphene, 1 to 3 parts of nano zinc oxide, 8 to 18 parts of ethylene-vinyl acetate copolymer, 8 to 12 parts of 3-aminopropyltriethoxysilane and 10 to 15 parts of ethyl acetate. The PP resin, the plant fiber starch, the calcium carbonate, the nano titanium dioxide, the silane coupling agent, the nano silver oxide, the graphene, the nano zinc oxide, the ethylene-vinyl acetate copolymer, the 3-aminopropyltriethoxysilane and the ethyl acetate are used as raw materials for preparing the environment-friendly PP plastic, and the prepared environment-friendly PP plastic has the advantages of being high in toughness, low in low-temperature brittleness, high in impact resistance, short in degradation period, and beneficial to environmental protection.