The present disclosure discloses a method for aligning liquid crystals of a PSVA liquid crystal display device, including the steps of: providing a first voltage to a gate of a thin film transistor for enabling it in a turn-on state; applying a second voltage to the source of the thin film transistor, and applying a third voltage to a color filter side common electrode and an array side common electrode, so as to generate an alternating current voltage difference between the source and the color filter side common electrode, and enable the liquid crystal molecules to be arranged according to predefined direction angles; curing the liquid crystal molecules. The method may enable the alignment of the liquid crystal molecules to be ideal, which is advantageous to the subsequent process of tilt angles, so as to enhance the efficiency and effect of the liquid crystal display.