The invention relates to the technical field of display, in particular to an array substrate, a manufacturing method of the array substrate and a display device. The array substrate comprises a first gate metal layer, a first gate insulating layer on the first gate metal layer, an active layer which is arranged on the first gate insulating layer and corresponds to the first gate metal layer, an etching barrier layer on the active layer, a source and drain metal layer comprising a source and a drain, a second gate insulating layer on the source and drain metal layer and a second gate metal layer on the second gate insulating layer, wherein the source and the drain are in contact with the two sides of the active layer respectively and are separated on the etching barrier layer. By means of the array substrate, the manufacturing method of the array substrate and the display device, the TFT characteristic can be optimized, the gate line resistance can be reduced, light irradiating the active layer can be shielded, IR Drop and TFT threshold voltage excursion and generation of the light leakage current of the active layer can be easily restrained, and the performance of the display device can be promoted.