The invention discloses an environment-friendly breathable TPU synthetic leather and a preparation method thereof. The environment-friendly breathable TPU synthetic leather comprises a decorative surface layer, a TPU surface layer, an adhesive layer and a base cloth layer. The decorative surface layer is coated on The treatment agent on the upper surface of the TPU surface layer is generated, and the TPU surface layer is combined with the base cloth layer through the adhesive layer. The components and parts by weight of the TPU surface layer are: 30 to 95 parts by weight of TPU particles; 3 to 95 parts by weight of the flame retardant 25 parts by weight; 2-15 parts by weight of pigment; 0-5 parts by weight of light stabilizer; 0-5 parts by weight of anti-scratch agent; 0-20 parts by weight of filler. The adhesive is a water-based polyurethane adhesive; the surface treatment agent is a water-based polyurethane surface treatment agent. Adopting the preparation method of extrusion casting, shaping first, then compounding, and negative pressure embossing, the products are environmentally friendly, non-toxic, low-odor, low-VOC, clear in structure, soft in hand, scratch-resistant, wear-resistant, hydrolysis-resistant, genuine leather Strong features.