The embodiment of the invention discloses an array substrate, a display unit and a control method thereof, belongs to the display technical field, and solves the technical problems that the H-line of a conventional narrow-frame liquid crystal display of a conventional grid drive circuit is poor, and the displaying effect is influenced. The array substrate comprises grid line groups and main grid lines, wherein, the number of the grid line groups is n, and the number of the main grid lines is n plus 1; each grid line group comprises a first grid line and a second grid line which are adjacent, a first transistor T1 is provided correspondingly to each first grid line, and a second transistor T2 and a switch element T3 are provided correspondingly to each second grid line; each first grid line and each second grid line in the grid line group i are connected with the main grid line i; a gate electrode of the T1 is connected with the first grid line, a source electrode is connected with a data cable, and a drain electrode is connected with a pixel electrode; the gate electrode of the T2 is connected with the T3 in a pixel unit, the source electrode is connected with the data cable, and the drain electrode is connected with the pixel electrode; in addition, one end of the T3 is connected with the main grid line i plus 1 and is used for controlling the switching-on and switching-off of the T2. The array substrate, the display unit and the control method thereof can be applied in the liquid crystal display.