The invention discloses an improved brick structure for a grate cooler parapet. The improved brick structure for the grate cooler parapet comprises a brick body, side wing plates are arranged on the two sides of the brick body, the top faces of the side wing plates are flush with the top face of the brick body, the height of each side wing plate is half that of the brick body, the section of each side wing plate is in an L shape, two symmetrical positioning columns are arranged on the top face of the brick body, two symmetrical positioning holes are formed in the bottom face of the brick body, and when upper and lower adjacent bricks are fixed, the positioning columns are plugged into the positioning holes. Original heat resistant steel palladium nails and castable casting are omitted, prefabricated bricks are adopted to be directly laid, and meanwhile prefabricated bricks are connected more stably and accurately.