The invention discloses polyester with high heat resistance and high toughness, a polyester product, and a preparation method and application of the polyester product. The preparation method comprisesthe step of copolymerizing bis (hydroxyethoxy) polycyclic aromatic hydrocarbon, binary acid or ester thereof and dihydric alcohol to prepare the high-heat-resistance and high-toughness polyester, andthe binary acid adopts thiophenedicarboxylic acid, furandicarboxylic acid, terephthalic acid and the like. According to the invention, dihydroxyethyl polycyclic aromatic hydrocarbon with excellent rigidity, high-activity hydroxyethyl and free-rotation oxygen ether bond is copolymerized with thiophene dioctyl phthalate, furan dioctyl phthalate and terephthalic acid or ester thereof, rigid alicyclic diol is introduced, and through the cooperation of the technical elements, the glass-transition temperature, toughness and visible light transmittance of the copolyester are effectively improved, sothe obtained copolyester has excellent properties of high glass-transition temperature, high transparency and high elongation at break, and can be widely applied to baby feeding bottle bodies, watercups, kitchen electrical products, hot-filled beverage bottles, optical base films, decorative materials, automobile parts and other products.