介绍了偏振紫外光诱导光聚物液晶取向的基本原理；对用于光控取向的取向层聚合物材料做了分类；把光控取向的取向机理从不同角度归纳为：体诱导和表面诱导、光聚合、光分解和光异构作用。 The basic principles of the liquid crystal orientation induced by polarized ultraviolet light are introduced. The orientation layer polymer materials used for photoalignment are classified. The orientation mechanism of photo-controlled orientation is summarized from different angles: body induction and surface induction, Photopolymerization, photodecomposition and photo-isomerization.