目的 提高基于海藻酸钠（SA）、壳聚糖（CS）和普鲁兰多糖（PUL）等3种天然多糖的复合可食性膜的理化性能。方法 采用层层静电沉积技术制备分别含有SA层和CS-PUL层（B1），SA-PUL层和CS-PUL层（B2）的双层膜，通过红外光谱（FTIR）、X射线衍射（XRD）、差示扫描量热法（DSC）对膜进行表征，并考察其水分阻隔性能、力学性能和透光性能等。结果 与单层膜相比，双层膜红外光谱中的关键基团峰发生了变化和偏移，结晶度改变，DSC曲线的吸热峰和放热峰也均发生位移，表明双层膜中各层之间并不是简单叠加，而是存在一定的静电相互作用；双层膜的拉伸强度显著增加，透光率降低，断裂伸长率和水蒸气透过率介于对应的各单层膜之间。结论 双层膜结合了各单层膜的优势，具有更优的理化性能，在食品保鲜包装领域具有一定优势。

The work aims to improve physicochemical properties of composite edible films based on three kinds of natural polysaccharides (sodium alginate (SA), chitosan (CS), pullulan (PUL)). Layer-by-layer electrostatic deposition technique was used to prepare bilayer films composed of B1 containing SA layer and CS-PUL layer and B2 containing SA-PUL layer and CS-PUL layer. The films were characterized by Fourier transform infrared spectrum (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), and the water barrier property, mechanical property and light transmittance were investigated. The results showed that, compared with monolayer films, the peak of key groups in the FTIR of the bilayer films changed and shifted; the crystallinity changed; and the endothermic and exothermic peaks of the DSC curve shifted, indicating that the layers in the bilayer films were not simply superimposed, but subjected to some electrostatic interaction. Tensile strength of the bilayer films increased significantly and light transmittance decreased. In addition, elongation at break and water vapor permeability were between the corresponding monolayer films. Therefore, the bilayer film combines the advantages of each monolayer film, and has better physicochemical properties, which has certain advantages in the field of food preservation and packaging.