The invention discloses an automotive trim flame-resistant material and a preparing method thereof. The material comprises, by weight, 50-80 parts of polypropylene resin, 20-60 parts of anilmomethyl triethoxy silane, 10-40 parts of glass fiber reinforced polyethylene terephthalate, 20-30 parts of N-ethyl-p-toluenesulfonamide, 40-50 parts of barium sulfate, 40-50 parts of polyvinyl alcohol, 10-30 parts of dimethyl terephthalate, 20-60 parts of paraformaldehyde, 40-50 parts of arsenic trioxide, 2-8 parts of potassium oxide, 10-20 parts of dicyanodiamine, and 20-40 parts of adipic acid dihydrazide. According to the preparing method, the polypropylene resin, the anilmomethyl triethoxy silane, the glass fiber reinforced polyethylene terephthalate, the N-ethyl-p-toluenesulfonamide, the barium sulfate, the polyvinyl alcohol, the paraformaldehyde, the arsenic trioxide, the potassium oxide, the dicyanodiamine and the adipic acid dihydrazide are evenly mixed through a high-speed mixing machine for plasticizing fusion, dimethyl terephthalate injection is conducted at the same time, and the constituents are extruded after being mixed. The flame resistance of the automotive trim flame-resistant material is high.