Ultra-high molecular weight polyethylene (UHMWPE) fibers grafted with acrylic acid and acrylamide were successfully prepared by means of 60Co γ-ray pre-irradiation grafting. UHMWPE fiber adsorbent containing dithiocarboxylic, amide and carboxylic groups was obtained by dithiocarboxylic reaction. Mass gain rate showed that the maximum grafting rate of acrylamide reached 300% when acrylamide was grafted onto UHMWPE fibers modified with acrylic acid, which was far more than when acrylamide was grafted alone. The results of adsorption performance test for Cu(II) ions exhibited that the prepared UHMWPE fiber adsorbent has excellent Cu(II) ions adsorption capacity. The maximum adsorbed Cu(II) ions amount to 341 mg g−1 (initial concentration of 400 mg L−1, time of 6 h). Moreover, the highest removal ratio of Cu(II) ions can reach 99.9%. [ABSTRACT FROM AUTHOR]