A bamboo mat board element with a double-layered construction, a constant dimension, each of the elements is formed with a projecting tenon at each of two adjacent sides, respectively, and a concave mortise at each of the other two adjacent sides, respectively, for inter-tenoning the elements of the mat board, in which a surface layer of the mat board is obtained by matting a plurality of mat board stuffs having different orientations, shapes, and sizes, while each of the mat board stuffs is obtained by matting a plurality of lumbers having a parallel orientation, respectively, to form a plurality of patterns having parallel stripes by specially matting at the longitudinal section thickness of the lumbers. A method for producing the bamboo mat board at least comprises steps as follows: cutting step, boiling for blanching step, drying step, rough shaving, bottom layer pre-forming step, adhesive applying and pressing step, pattern selecting step, matting step, and refined shaving, etc. The sandwich mat board is then formed by pressing.