Abstract: Amidoxime polyacrylonitrile (AOPAN)-β-cyclodextrin (β-CD) nanofiber membranes were synthesized in one step using polyacrylonitrile (PAN) and β-CD as raw materials by in-situ amidoxime modification with hydroxylamine hydrochloride and then electrospinning technology. Evaluating by morphology and adsorption capacity, the preparation condition of modification was optimized. The morphology, composition and properties of the membranes were characterized by SEM, FTIR and surface tension meter. The results show that under the optimized modification process conditions, which the molar ratio of cyanogroup to hydroxylamine is 1∶1 and the modification time is 2 h, the morphology distribution of AOPAN-β-CD nanofiber membrane is more uniform and the fiber diameter is about 230 nm, and the adsorption capacity of the fiber membrane reaches 78.62 mg/g.