Ag/AgCl-based plasmonic photocatalysts have received much attention as emerging visible-light-driven photocatalysts, wherein those characterized by 1D morphology have aroused great expectations. Most of the current existing protocols for the fabrication of 1D materials, however, suffer from either multistep tedious synthesis processes or the requirement of rigorous experimental conditions. A one-pot fabrication method feasible under ambient conditions is strongly desired. By means of a surfactant-assisted protocol, we report herein that Ag/AgCl structures of near-spherical and 1D morphology could be controllably produced. We show that near-spherical Ag/AgCl species could be produced immediately after dropping an AgNO3 aqueous solution into an aqueous solution of cetyltrimethylammonium chloride (CTAC) surfactant under stirring. Interestingly, we show that these initially formed near-spherical species could automatically evolve into 1D Ag/AgCl fibers simply by extending the stirring time under ambient conditions. In our new protocol, CTAC works not only as a chlorine source but also as a directing reagent to assist the formation of 1D Ag/AgCl structures. Moreover, we demonstrate that compared to near-spherical structures, our Ag/AgCl fibers could display boosted catalytic performances towards the photodegradation of the methyl orange pollutant under visible light irradiation. Our work might launch an easy method for the construction of fibrous Ag/AgCl architectures of superior photocatalytic reactivity, and it also provides deep insights into the surfactant-assisted synthesis.