Abstract：The major chemical components of DS1 samples are Al2O3 64.31%，SiO2 8.92%, A/S 7.11，and TS0.30%. After this sample was treated by the roasting wet pre-desilicification method, the A/S ratio increased from 7.11% to 26.37%, Al2O3 increased from 63.41% to 78.53%, and TS decreased from 0.30% to 0.11%. The roasting temperature was 280 ℃ and the time span was 60 minutes, the ingredient ak was 1.45 and the alkali concentration was 220 g/l. Under the best stripping condition in which the lime additive amount is 4%, the absolute stripping rate of Al2O3 was 95.52% and the relative rate was 99.59%, the stripping rate of Ga was 91.63%. More than 99% Al2O3 could be obtained when the dissolved substance was sintered at the temperature of 1100 ℃ for 2 hours. All the other indexes were better than the indexes of aluminium oxide of industrial standard YS/T274-1998AO-1.The GS1 sample, after roasting wet pre-silicification treatment, A/S increased from 5.31 to 18.88, Al2O3 increased from 61.37% to 80.09%, SiO2 decreased from 11.55% to 4.26% and TS decreased from 1.20% to 0.16%. These data suggest that, after the treatment, the high-sulfur low-alumina silicified bauxitic ore absolutely can attain the requirement for aluminum-silicon ratio and sulfur content of Bayer process, indicating the application prospect of the high-sulfur low-alumina silicified bauxitic ore.