The invention relates to aggregates used for preparing tin bath bottom bricks and a preparation method thereof and the tin bath bottom bricks, and belongs to the technical field of refractories. The aggregates are silicon-aluminium clinkers; the mass percentage of Al2O3 in the silicon-aluminium clinkers is 42-47; the volume density of the silicon-aluminium clinkers is 2.1-2.5 g/cm3, the apparent porosity is 0.65-10%. The aggregates have the advantages that the thermal conductivity coefficient, hydrogen diffusivity, elastic modulus and linear expansion coefficient of the tin bath bottom brickscan be reduced, the tin bath bottom bricks are allow to provide with proper volume density and lower apparent porosity, the aggregates have long service life when applied to the tin bath bottom bricks, no nepheline is generated in the using process, the heat preserving effect is good, and the thermal utilization efficiency can be significantly improved.