The invention relates to a method for preparing architectural ceramic bricks by wet-casting molding of granite waste wet. The method comprises the following steps: by taking granite wastes as main raw materials, by taking water as a dispersing medium, by taking carrageenan, sesbania glue and low polymer sodium polyacrylate as additives, mixing to obtain slurry; preparing architectural ceramic bricks by adopting a wet-casting molding process, drying and fettling, firing at the temperature of 1140-1180 DEG C, and cooling to obtain the architectural ceramic bricks with the breaking strength of 50-70MPa. The method is simple in preparation process; compared with the traditional architectural ceramic dry pressing process at present, the method has the advantages that large tonnage press and spray material preparation are saved, dust and noise pollution are reduced, the production cost is low, hard brittle materials serve as main raw materials, the problem that clay and other traditional high-quality ceramic raw materials are increasingly scarce is relieved, and the problem that a green ceramic body molded by using the hard brittle materials is low in strength is solved. Moreover, compared with similar architectural ceramics, the architectural ceramic bricks are low in price, and higher economic benefits can be brought.