The invention discloses an array substrate, a display panel and a display device. The array substrate comprises a substrate, a plurality of grid lines, a plurality of data lines and a public electrode, wherein the plurality of grid lines and the plurality of data lines are arranged on the substrate and intercross with each other to form a plurality of pixel units which are arranged in an array manner; the public electrode is arranged on the pixel units and is plane-shaped; the public electrode comprises a plurality of strip-shaped slots in the areas corresponding to the pixel units; long axes of the plurality of strip-shaped slots corresponding to pixel units in one same row are parallel to one another; extension lines of long axes of the strip-shaped slots corresponding to any two adjacent rows of pixel units intersect with one another; in the plane with the public electrode, the included angle between the long axis of each strip-shaped slot and the direction perpendicular to the grid lines is set as a first angle; the first angle is greater than or equal to 6 degrees and is smaller than or equal to 8 degrees. Liquid crystal molecules which cannot be normally orientated in the display panel can be reduced, so that the light leak phenomenon happening when the display panel and the display device are in a black state is reduced.