The invention relates the method of extracting aluminium from high-silicon siliceous mineral. The method comprises the following steps: mixing the aluminous ore and sulfuric acid, baking, leaching with water, filtering leachate, getting aluminium sulphate solvent, thickening filter liquor, separating out aluminium sulphate, drying, dewatering, getting anhydrous aluminium sulphate; calcining aluminium sulphate, and getting Al2O3. The invention can extracte aluminium from high-silicon siliceous mineral, coal gangue, coal ash, China clay, andalusite, feldspath, ganister, nepheline and vermiculite without baking. The method has the advantages of simple technology, little corrosion, easy operation and high recovery ratio.