The present invention relates to an AMOLED array substrate, a manufacturing method thereof and a display device. The AMOLED array substrate includes at least one first auxiliary line provided in the same layer as but not intersecting with pixel electrodes; and at least one second auxiliary line provided in the same layer as source and drain electrodes but not intersecting with data lines and the source and drain electrodes, wherein: projections of the first and second auxiliary lines on plate electrode are within projection of pixel define layer and at least partially overlap; and the first auxiliary line is electrically connected to the second auxiliary line via a first via hole and to the plate electrode via a second via hole formed in pixel define layer, wherein projection of the first via hole on the plate electrode is within overlapped projection of the first and second auxiliary lines.