目的 用简易、经济的方法制备透明柔性、可折叠、力学性能良好的茶梗纳米纤维素基磁性复合膜。方法 以茶梗纳米纤维素晶体（CNCs）为模板，共沉淀合成磁性CNCs；随后将磁性CNCs分散到茶梗纳米纤维素纤丝（NCFs）溶液中；最后通过真空抽滤的方法制备磁性复合膜。结果 磁性CNCs在不需要任何分散剂的情况下，可以均匀地分散在水溶液中，具有良好的超顺磁性；磁性复合膜具有良好的光学、力学和磁学性能，当NCFs质量分数为60%时，透光率、拉伸强度和磁化强度分别达到71.3%，75.03 MPa和12.96 A?m2/kg。结论 制备的磁性CNCs具有良好的分散性和磁学性能；磁性复合膜具有较好磁学和力学性能，可考虑在电磁屏蔽、磁电开关等领域进行应用。

The work aims to prepare nanocellulose based magnetic composite film of tea stalk with flexible, transparent and good mechanical properties in a convenient and economic way. First, cellulose nanocrystals (CNCs) from tea stalk were used as templates to synthesize magnetic CNCs (MCNCs). Then, the MCNCs were dispersed in the solution of nanocellulose fibrils (NCFs) from tea stalk. Finally, magnetic composite film was prepared by vacuum filtration method. The magnetic CNCs, which had good superparamagnetism, could be evenly dispersed in the solution with no dispersing agent. The magnetic composite film had good transmittance, mechanical property and magnetic property. The transmittance, tensile strength and magnetization intensity were respectively 71.3%, 75.03 MPa and 12.96 A?m2/kg when the mass fraction of NCFs was 60%. The magnetic CNCs have good dispersion and magnetic property. The magnetic composite film has better magnetic and mechanical properties and it may be considered to be applied in the fields of electromagnetic shielding and magnetoelectric switches.