The invention discloses an easily-positioned fast wall building brick and belongs to the field of construction materials. The easily-positioned fast wall building brick comprises a brick body which isa cube, a top groove is formed in the top face of the brick body, and a bottom groove is formed in the bottom face of the brick body. The projection areas of the top groove and the bottom grooves areoverlapped, and a through internal grouting channel is formed between the top groove and the bottom groove. Positioning blocks are arranged on the top face of the brick body in a bulged mode, and positioning grooves are formed in the bottom face of the brick body in an internally sunken mode. When every two adjacent fast wall building bricks are spliced in the up-down direction, the positioning blocks of one of the fast wall building bricks are inserted into the positioning grooves of the other fast wall building brick. The speed of wall building by masons can be obviously increased, and meanwhile mutual splicing and positioning are more accurate.