Abstract: A carbonized brick of recycled concrete powders and a preparation method thereof are provided, belonging to the field of concrete materials. The preparation method includes: adding composition A to a liquid storage tank; introducing composition B into the liquid storage tank to react with a solid waste solution to generate calcium bicarbonate solution; filling recycled powders into a molding die, decomposing the calcium bicarbonate solution by heat, reacting generated carbon dioxide with calcium ions leached from a C—S—H gel in the recycled powders to produce calcium carbonate, and precipitating, crystallizing and cementing in the molding die together with calcium carbonate produced by decomposing calcium bicarbonate solution, and resulting in strength of the recycled powders.