Poor thermal stability as a bottleneck has limited the development of liquid crystal photo - alignment technique . the intrinsic reason is that the photosensitive polymer has large space resistance and decreases the reaction degree of the directional photo - polymerization . the effective solution is focused in the increase of orientational order of photo - alignment film 光控取向技术瓶颈问题是稳定性差,其根本原因是光敏高分子空间位阻太大,定向交联的反应度太低,有效解决方法应是降低位阻,提高定向交联度和取向膜分子链段的有序度。