Electroless Ni and Ni-P-B plating were conducted respectively on aromatic polysulfonamide (PSA) fibers following a new chlorine-aided silver activation system in the present work. Firstly, PSA fibers were treated in NaClO-HCl solution to impart chlorine to the surface area followed by immersion in AgNO3 solution to convert the chlorine to AgCl particles. After subsequent reduction of AgCl to metallic Ag seeds in NaBH4 solution, electroless Ni and Ni-P-B plating were performed respectively. These two kinds of adherent and continuous coatings activated and anchored by the silver seeds, which were both resistant against sonication, were deposited onto PSA fibers with different electrical, magnetic, electromagnetic shielding, and corrosion resistance properties. Both plated PSA fibers can act directly as electromagnetic interference shielding and static charge dissipation materials, or act as excellent base layers for other subsequent metallic coatings according to different requirements, and then show great potential applications in coaxial cables and wear protection for aerospace, aviation, microelectronics, military industry and telecommunications.