The present invention provides a display device and a method for controlling a grating thereof, and belongs to the field of display technology, and can overcome the problem in which electrodes of the grating substrate require high fabricating accuracy and are difficult to fabricate due to the arrangement of a pixel array. The display device at least comprises a pixel array and a grating, an odd-numbered row of sub-pixels and a neighboring even-numbered row of sub-pixels are offset in a longitudinal direction by a preset length, a first substrate of the grating comprises a plurality of electrodes, each electrode comprises a plurality of segments which are continuous and are offset in a segment-wise manner by a predefined length from an end to the other end of the electrodes. Since the pixels and the grating are arranged in a corresponding manner, the electrodes of the grating substrate have an increased width, requirements for accuracy of the process for fabricating the electrodes are reduced, and the fabrication difficulty is reduced. By turning on and off the grating, a switch of the display device between 2D and 3D display can be realized.