The invention discloses an array substrate of a liquid crystal display device, which comprises scanning wires, data wires, pixel cells as well as pixel electrodes and transistors which are arranged in the pixel cells, wherein every two lines of pixel cells in the array substrate can configure one scanning wire, and every one row of pixel cells configures two data wires; the array substrate also comprises first repairing wires and second repairing wires, which are arranged in different layers, and the first repairing wires are arranged between every two adjacent rows of pixel cells, are extended along the direction of the data wires and are broken on each of the crossed parts of the first repairing wires and the scanning wires; the second repairing wires are arranged on the broken parts ofthe first repairing wires, stripe over the scanning wires corresponding to the broken parts and extend along the direction of the data wires. The invention also discloses the liquid crystal display device applying the array substrate as well as a repairing method used for the array substrate. The liquid crystal display device, the array substrate and the defect repairing method thereof can solve the problem of lower yield caused by the defects of the data wires.