The invention relates to a liquid crystal display device and a driving method thereof. The liquid crystal display device comprises a first base plate, a second base plate and liquid crystal molecules positioned between the first base plate and the second base plate. A first common electrode is arranged on the first base plate. A pixel electrode and a second common electrode are arranged on the surface of the second base plate over the first common electrode; the second common electrode surrounds the pixel electrode; a slit is formed between the second common electrode and the pixel electrode;and when the second common electrode obtains a driving signal, an electric field for driving the liquid crystal molecules positioned in the slit to pre-tilt is formed between the second common electrode and the pixel electrode. As the slit, the second common electrode and the pixel electrode are all formed through exposure development, the electric field required for the pre-tilt of the liquid crystal molecules is obtained under the situation that no process is added; and compared with the conventional MVA (Machinery Vibration Analysis) method and the conventional PVA (Patterned Vertical Alignment) method, the production cost and the process complexity are reduced.