A liquid crystal grating module (3) and a two dimension-three dimension switchable liquid crystal display device using the same. The liquid crystal grating module (3) comprises a first transparent electrode layer (20) and a second transparent electrode layer (50). The first transparent electrode layer (20) and the second transparent electrode layer (50) are provided with interval. The first transparent electrode layer (20) comprises a plurality of lateral electrode bars (202,204). The second transparent electrode layer (50) comprises a plurality of vertical electrode bars (502,504). The lateral electrode bars (202,204) and the vertical electrode bars (502,504) are alternately superposed on each other with interval to form a grating structure. The vertical electrode bars (502,504) have three different widths in the direction vertical to the liquid crystal display pixels.