An array substrate, a display device and a driving method thereof are provided. In the array substrate, in a first pixel unit constituting a display unit group, a TFT of the first sub-pixel and a TFT of the second sub-pixel are connected to the same data line. In the second pixel unit of the display unit group, a TFT of the second sub-pixel and a TFT of the third sub-pixel are connected to the same data line. A distance along a direction of the gate line between adjacent two sub-pixels having a data line between them is a first shielding size, a distance along the direction of the gate line exists between adjacent two sub-pixels having no data line between them is a second shielding size, and the second shielding size is smaller than the first shielding size.