The disclosure provides a double-side display, a display module and a TFT array substrate thereof, the TFT substrate includes two graphene display units disposed opposite and a reflective layer disposed between the two graphene display units. Compared with a conventional technique, according to the double-side display, the display module and the TFT array substrate thereof, the graphene display units are disposed on the two sides of the reflective layer respectively to prevent influence between light of the two sides of the reflective layer, brightness of two display units is improved due to reflective light from the reflective layer; the structure of the double-side display is simpler, and the volume is reduced significantly, which are benefit for thinning and lightening the double-side display.