The invention relates to a high-temperature resistant three-component polyurethane adhesive and a preparation method thereof, which belongs to the technical field of polyurethane. The high-temperatureresistant three-component polyurethane adhesive comprises a component A, a component B and a component C, wherein the mixing mass ratio is 50 to 200:100:1 to 5; the component A consists of high-temperature-resistant polyester polyol, a catalyst and a high-temperature-resistant auxiliary agent; the component B is an isocyanate component obtained by modifying aliphatic diisocyanate or alicyclic diisocyanate with polyether polyol, and the mass fraction of the isocyano group is 12% to 20%; component C is glycerol or trimethylolpropane; the high-temperature-resistant polyester polyol is prepared from an alicyclic polybasic acid and alicyclic polyol through esterification and polycondensation. The high-temperature resistant three-component polyurethane adhesive has the advantages of low viscosity, easiness in sizing, stable adhesive property and widening the high-temperature applicability of the polyurethane adhesive; The high-temperature resistant three-component polyurethane adhesive alsoprovides a simple and easy preparation method.