The invention provides an array substrate, a display panel, and a manufacturing method for the array substrate. The array substrate comprises a plurality of TFTs arranged in a matrix, a planarization layer formed on the plurality of TFTs, a common electrode layer formed on the planarization layer, a passivation layer formed on the common electrode layer, and a pixel electrode layer formed on the passivation layer. The pixel electrode layer is electrically connected with the drain electrode of a corresponding TFT through the contact hole of the passivation layer, the contact hole of the common electrode layer, and the contact hole of the planarization layer which are arranged in sequence. The planarization layer comprises a flat region and a slope region which transits from the edge of the contact hole of the planarization layer to the flat region. The edge of the contact hole of the common electrode layer is in the slope region of the planarization layer. The edge of the common electrode layer is in the slope region of the planarization layer, so coverage of the passivation layer is improved, and defect that the edges of the common electrode layer tilt or defect of dark spots since the slope of the passivation layer is too thin are prevented.