Belonging to the field of polyurethane high polymer materials, the invention relates to a transparent polyurethane material and a preparation method. The transparent polyurethane material takes acetone as the solvent, adopts ethylene glycol as the chain extender, and uses stannous octoate as the catalyst, and is prepared by polymerization of xylose and aliphatic isocyanate. The preparation method includes: (by mass), taking 900-1300 parts of tetrahydrofuran as the reaction solvent, reacting 20-50 parts of xylose (with a moisture content of less than 0.003%) with 80-150 parts of diisocyanate under the action of the catalyst and chain extender to obtain a polyurethane solution, subjecting the solution to film casting on a polyfluortetraethylene plate to obtain a film, and conducting curing at room temperature for 6-10h, thus obtaining the transparent polyurethane material. The synthesized polyurethane material has acid resistance, alkali resistance, light transmission, good oil resistance and mechanical properties, can be used as outer coatings for automobile front and rear lamp shades, safety glass, instruments and equipment, and daily use articles, and plays the role of dustproofness, oil pollution resistance, corrosion prevention and other surface protection.