An array substrate, a liquid crystal display and a control method thereof are disclosed. The array substrate includes scanning lines, data lines, pixel units, and common lines. Each common line is disposed along a row of pixel units. The array substrate also includes a common voltage supply line, and dual-channel selection switches each having an output terminal connected to a set of common lines, two input terminals connected to a common voltage high level supply line and a common voltage low level supply line respectively to selectively apply a high level or a low level to the common lines, thereby avoiding delay of the common voltage Vcom and the Vcom drift during a display mode and improving the display effect for an image.