A creative method for fabricating environmentally-benign multifunctional wool fibers was established and reported. Through coating the wool fibers with ε-polylysine, the surface morphology and biochemical properties of the fibers were altered, enhancing their antimicrobial, hygroscopic and finished properties. The process of ε-polylysine coating was dependent on the solution environment, which influenced the electrostatic interactions between ε-polylysine molecules and wool fibers. The results showed that a maximum ε-polylysine coating (23.60 mg/g) on the surface of wool fibers was reached when wool fibers were soaked at 50 ℃ for 2 h in the solution with 10% on weight of fabric (owf) ε-polylysine and pH 8.0. The coated wool fiber showed promising antimicrobial rates of 96.98% and 97.93% against Escherichia coli and Micrococcus luteus, respectively. The wool fiber coated with the ε-polylysine was more hydrophilic than the uncoated wool fabrics. The functional wool fibers after water scrubbing for two times still have good antibacterial efficiency against Escherichia coli and Micrococcus luteus, and antimicrobial rates were 96.77% and 97.33%, respectively. This study shows that wool fibers modified by the nontoxic ε-polylysine have a great potential to be used in constructing multifunctional textiles.