Uranium extraction from seawater is considered as an efficient strategy to meet the increasing demands of uranium. Amidoxime has been reported as one of the most efficient groups for uranium affinity. Herein, ami-doximated cellulose fibers were synthesized by grafting polyacrylonitrile (PAN) onto cellulose fibers followed by amidoxime modification. The amidoximated cellulose fibers showed maximum adsorption capacity of 52.88 mg g(-1) (pH = 5.0), and its static adsorption process was well fitted with Langmuir model and Pseudo-second-order kinetics. The adsorption mechanism was attributed to the chelating reaction between uranyl complexes and amidoximated cellulose fibers. The prepared fibers were further fabricated into nonwoven membrane for dy-namic adsorption, and the breakthrough curves were well fitted to Dose-Response model. The amidoximated cellulose fiber membrane showed a good adsorption capacity of 1.22 mg g(-1) at pH 8.0 after filtrating 10.0 L simulated seawater, demonstrating promising efficient engineering materials for uranium extraction from sea-water.