The existence of organic impurities in bauxite significantly hampers the regular production of alumina. This study proposes a low-temperature ultrasonic-enhanced alkali leaching to directly separate organic impurities from bauxite, and purify the leaching solution through H2O2 oxidation and CaO precipitation. Under the optimal conditions of 550W ultrasonic power, 80 °C, 60min, and 200g/L NaOH concentration, the leaching rate of organic carbon in bauxite is 91.02%, which is 19.01% higher than conventional alkali leaching, and the organic carbon content in the bauxite decreased from 0.59% to 0.06% after leaching. Kinetic studies indicate that the limiting factors of the leaching rate vary under different leaching temperatures and leaching times. Characterization of bauxite before and after leaching using various detection techniques demonstrates the effective separation of organic impurities while basically no loss of alumina and increasing the alumina to silica ratio to 34.13. Subsequently, H2O2 and CaO are introduced to the leaching solution with 20% and 800mL/g, respectively. The oxidation process under 550W ultrasonic power at 90 °C for 60min achieves an 71.35% removal rate of organic carbon. GC-MS analysis confirms the successful removal of the main organic substances in the leaching solution, while XRD analysis of the oxidation residue indicates that organic substances are ultimately removed as CaC2O4·H2O and CaCO3. Additionally, a proposed free radical reaction mechanism of H2O2 oxidizing organic substances is discussed. In conclusion, this study providing valuable insights for the removal of organic pollutants in the alumina production process.