Biodegradable synthetic leather and preparation method thereof

The invention relates to biodegradable synthetic leather. The biodegradable synthetic leather comprises a base fabric, a synthetic leather bottom layer and a synthetic leather surface layer in sequence, wherein the base fabric is a soybean fiber nonwoven fabric; the synthetic leather bottom layer is prepared from, by weight, 10-15 parts of water, 60-100 parts of water-based polyurethane resin, 110-120 parts of bagasse tapioca starch polylactic acid, 2-4 parts of methylene bisstearamide, 1-3 parts of butyl stearate, 0.2-0.5 part of sodium carboxymethyl starch, 20-50 parts of rice bran, 1-2 parts of nano-zinc oxide, 5-10 parts of foaming agent and 1-4 parts of N,N-dimethyldodecylamine-N-oxide; the synthetic leather surface layer is prepared from, by weight, 30-50 parts of polyethylene, 13-20parts of starch, 5-10 parts of protein powder, 1-2 parts of moisturizing agent, 3-5 parts of soybean protein powder and 5-9 parts of cross-linking agent. The obtained synthetic leather is degradable,free of environmental pol