A method for setting a pre-tilt angle of liquid crystal molecules includes (1) providing liquid crystal material, a CF substrate, and a TFT substrate; (2) arranging the substrates to form a gap therebetween in which the liquid crystal material is filled to form a liquid crystal cell; (3) providing a drive control circuit that generates driving voltages and connecting the drive control circuit to the TFT substrate; (4) providing a small-amplitude oscillation device and an irradiation intensity variable ultraviolet light source and positioning the liquid crystal cell on the oscillation device; (5) activating the oscillation device to cause the liquid crystal cell to make small-amplitude oscillation and conducting on the drive control circuit to supply driving voltages to drive the liquid crystal material, the ultraviolet light source being applied to irradiate the liquid crystal cell with ultraviolet lights of different intensities; and (6) repeating step (5) for at least one time.