An array substrate, a manufacturing method thereof and a display device are provided by the present disclosure. The manufacturing method includes: providing a base substrate; forming a plurality of pixel electrodes on the base substrate, in which the operation of forming the plurality of pixel electrodes includes: depositing a first transparent conductive film, and forming the plurality of pixel electrodes and a connection unit for connecting adjacent pixel electrodes by patterning the first transparent conductive film; forming a passivation layer on the plurality of pixel electrodes, and patterning the passivation layer to expose at least a portion of the connection unit; and processing the exposed portion of the connection unit, so that the plurality of interconnected pixel electrodes are electrically insulated.