TiO₂-based fibrous membranes as plasmonic heterojunction photocatalysts would hold great promise in the field of water disinfection, however, it still existed a great challenge to design and construct such materials. Here, we presented the fabrication of continuous, hierarchical, and easy-to-recycle flexible Ag₂C₂O₄/TiO₂ heterostructured nanofibrous membranes (NMs) that were composed of thorn-like nanofibers through electrospinning technique followed by successive ionic layer adsorption and reaction (SILAR) process. Ag₂C₂O₄ nanoplates were firmly anchored on the surface of TiO₂ and the obtained Ag₂C₂O₄/TiO₂ heterojunction photocatalysts underwent a silent-to-active transition of visible-light response under light irradiation due to the surface plasmon resonance (SPR) effect of Ag nanoparticles derived from Ag₂C₂O₄, forming a new plasmonic heterojunction photocatalyst. By virtue of the hierarchical structure, enhanced visible light absorption and efficient charge carriers separation, Ag₂C₂O₄/TiO₂ NMs possessed high bactericidal efficiency of >99.999% within 30 min, strong reactive oxygen species (ROS) producing capability (1510 μg g^-1 and 659 μg g^-1 for superoxide radicals and hydroxyl radicals, respectively), and good reusability. This work may offer new insights into the design of antibacterial materials for pathogenic microorganism-contaminated water purification.