The invention discloses an array substrate preparation method, an array substrate and a display device. The method comprises the steps that multiple thin film transistors which are arranged in arraysare arranged on a substrate; a first transparent electrode layer is deposited on the substrate, and first composition technology processing is performed on the first transparent electrode layer so asto form multiple first electrodes which are connected with the drain electrodes of the thin film transistors and connecting electrodes which are connected with the adjacent first electrodes; a functional structure is arranged on one side, which is away from the substrate, of the first transparent electrode layer; and second composition technology processing is performed on the connecting electrodes, and the connecting electrodes are disconnected so that convex connecting parts are enabled to be formed on the edges of the first electrodes. Therefore, various defects caused by electrostatic breakdown in the preparation process of the array substrate can be eliminated by using the simple preparation technology.