The invention discloses an array substrate, a manufacturing method thereof and a liquid crystal display. The array substrate comprises a substrate, wherein data wires and grid lines, which are arranged in a crisscross pattern for forming a plurality of pixel units, are formed in a pixel region of the substrate, each pixel unit comprises a switch element, a pixel electrode and a public electrode, and the public electrodes have narrow slots and are arranged in a whole-block pattern in the pixel region, wherein public electrode wires are further formed in the pixel region, and the public electrode wires are communicated with the public electrodes. The public electrode wires are formed in the pixel region of the array substrate of the liquid crystal display, the public electrode wires are communicated with the pubic electrodes, and the public electrode wires and the public electrodes can form a parallel-connected circuit, thereby reducing the resistance of the public electrodes, further reducing RC (resistance-capacitance) signal delay of the public electrodes, improving the load capacity of public voltage signals, further weakening the crosstalk phenomenon and improving the image quality of the liquid crystal display.