Disclosed are a liquid crystal display device and a testing method thereof. The liquid crystal display device includes a plurality of scan lines, and a plurality of data line sets crossing the scan lines, where each data line set includes a first data line, a second data line, and a third data line. The device also includes a shorting bar for the data lines, a first data switch control line and a second data switch control line. Through holes are not used to connect the data lines and the shorting bar, thus disadvantages of display devices caused by defects in through holes is eliminated. Additionally, the area for testing structures is decreased, so that a small-sized liquid crystal display devices can be produced.