A fabrication method of a grating substrate, comprising: forming an array of comb-shaped, opaque touch electrodes (1, 2) and a plurality of first conductive bridges on a base substrate, wherein the array of touch electrodes (1, 2) comprises a plurality of first touch electrodes and a plurality of second touch electrodes, wherein each of the plurality of first touch electrodes and each of the plurality of second touch electrodes are disconnected from each other, and the plurality of first touch electrodes in the array are connected to each other by the first conductive bridges; forming an insulating spacing layer on the base substrate on which the array of the touch electrodes (1, 2) and the plurality of first conductive bridges are formed on the base substrate, the insulating spacing layer covering the first conductive bridges; and forming second conductive bridges on the insulating spacing layer, the plurality of second touch electrodes in the array being connected to each other by the second conductive bridges, characterized in that the base substrate is a color filter substrate, and in each of the comb-shaped touch electrodes (1, 2), a connection bar for connecting comb teeth corresponds to a black matrix of the base substrate, wherein the comb teeth of the plurality of first touch electrodes and the comb teeth of the plurality of second touch electrodes are parallel to each other, and the plurality of first touch electrodes and the plurality of second touch electrodes are used as a touch electrode of a touch screen and a 3D slit grating, such that both a touch function and a 3D light-splitting function are achieved at the same time. forming an array of comb-shaped, opaque touch electrodes (1, 2) and a plurality of first conductive bridges on a base substrate, wherein the array of touch electrodes (1, 2) comprises a plurality of first touch electrodes and a plurality of second touch electrodes, wherein each of the plurality of first touch electrodes and each of the plurality of second touch electrodes are disconnected from each other, and the plurality of first touch electrodes in the array are connected to each other by the first conductive bridges; forming an insulating spacing layer on the base substrate on which the array of the touch electrodes (1, 2) and the plurality of first conductive bridges are formed on the base substrate, the insulating spacing layer covering the first conductive bridges; and forming second conductive bridges on the insulating spacing layer, the plurality of second touch electrodes in the array being connected to each other by the second conductive bridges, characterized in that the base substrate is a color filter substrate, and in each of the comb-shaped touch electrodes (1, 2), a connection bar for connecting comb teeth corresponds to a black matrix of the base substrate, wherein the comb teeth of the plurality of first touch electrodes and the comb teeth of the plurality of second touch electrodes are parallel to each other, and the plurality of first touch electrodes and the plurality of second touch electrodes are used as a touch electrode of a touch screen and a 3D slit grating, such that both a touch function and a 3D light-splitting function are achieved at the same time.