Building waste shale brick and preparation method thereof

The invention discloses a building waste shale brick and a preparation method thereof. The building waste shale brick is mainly prepared from the following raw materials in percentage by mass according to the following steps: adding 10% of building waste, 3-12% of quicklime powder, and aluminite powder or iron powder with the mass ratio of 0.5-1.5 to shale powder; adding water to the raw materials, mixing into a wet material with the moisture content of 10%-15%, and preparing a green brick; drying, roasting, carrying out heat preservation and cooling, so as to prepare a lightweight shale brick, wherein the extrusion molding pressure is 20-25MPa; and the moisture content of the dried green brick is 4%-5%; and controlling the roasting temperature at 1,000-1200 DEG C, and keeping for 420-720 minutes, so as to prepare the building waste shale brick. The building waste shale brick has the advantages that the anti-freezing performance, the folding resistance and the compressive property are improved; and the crack resistance, the sound insulation property and the strength are improved.