Inorganic aluminium salt waterproofing agent (liquid) is a mortar waterproofing additives, waterproofing, water reduction, anti-cracking, anti-stretching, anti-bending, early strength, anti-seepage, anti-leakage, moisture, acid and alkali resistance, etc., specifically used for the construction of the structural surface layer of the steel permanent waterproofing to form a solid dense water-repellent material, filling, blocking concrete, mortar in the hardening process of the formation of capillary pore space and water channels, with a strong hydrophobicity and moisture repulsion, thus giving excellent waterproof performance of concrete structures and cement products. Moisture rejection, thus giving concrete structures and cement products excellent waterproof performance.