An array substrate, a display panel, a display device and a manufacturing method thereof. The array substrate includes: a substrate; a plurality of thin film transistors spaced apart from each other and disposed in an array on the substrate; a first passivation layer on the plurality of thin film transistors; and a plurality of touch signal lines and a pixel electrode layer on the first passivation layer, where the pixel electrode layer includes a plurality of pixel electrodes spaced apart from each other and disposed in an array, and is disposed in the same layer as the touch signal lines and electrically insulated from the touch signal lines.