Method for preparing baking-free brick from sludge of urban sewage treatment plant

The invention discloses a method for preparing a baking-free brick from sludge of an urban sewage treatment plant. The method comprises the following steps: carrying out filter pressing, drying, incineration and crushing on the sludge obtained after sewage is treated by the urban sewage treatment plant to form sludge ash; sludge ash, limestone, copper slag and clay are placed in a ball mill to be subjected to ball milling, the mixed powder is mixed with water and then pressed into the same size, then drying is conducted to obtain a mixture, the mixture is calcined and then crushed, gypsum is added to be mixed and ground to obtain powder, and the powder replaces fly ash according to the replacement mass of 10-40% to be made into the baking-free brick. The prepared baking-free brick has the advantages of being excellent in compression resistance, good in water absorption performance, environmentally friendly and the like, can replace sintered bricks and baking-free bricks prepared through traditional methods, i