A new alignment technology was proposed here. Substrates coated with polyvinyl alcohol (PVA) and methyl orange (MO) layer were illuminated by a linearly polarized laser for certain time. Subsequently, a liquid crystal (LC) cell was assembled with the polarized direction of the illuminating light of both substrates mutually perpendicular, from which a twist nematic (TN) alignment of LC molecules has been got. When a beam of linearly polarized light transmits through the LC cell, the polarization direction will rotate 90°. After the laser illumination, the twist nematic structure of the LC cell keeps unchanged after a number of shots of high power laser pulses.