目的 选用羟丙基甲基纤维素（HPMC）和单宁酸（TA），通过氢键层层组装技术在聚乳酸（PLA）薄膜表面构建具有紫外屏蔽功能的透明涂层。方法 采用偏光显微镜观察薄膜表面和断面形貌，采用紫外-可见光光谱仪测试紫外屏蔽性能，采用电子万能试验机测试薄膜的力学性能。结果 与PLA原膜相比，随着组装层数的增加，紫外屏蔽性能也随之增强，透明性基本不变，力学性能略有下降。结论 为设计制备透明且具有屏蔽紫外线功能的包装薄膜涂层提供了一定的实验及理论依据。

The work aims to construct the UV-shielding and transparent coating on poly(lactic acid) (PLA) film via hydrogen-bonded layer-by-layer assembly of hydroxypropyl methyl cellulose (HPMC) and tannic acid (TA). The morphologies of the surface and cross-section of the film were observed by the polarized optical microscopy (POM), the UV-shielding property was measured by the Ultraviolet-visible (UV-vis) spectrophotometer, and the mechanical property of the film was measured by the universal electronic testing machine. Compared with the original PLA film, with the increase of the number of assembly layers, the UV-shielding property was increased, the transparency was almost unchanged, and the mechanical properties decreased slightly. Some experimental and theoretical basis is provided for the design and preparation of UV-shielding and transparent coating on the packaging film.