In order to restrain the bacterium to reproduce on the textile and do harm to the human health, the antibacterial wool-fibers can be prepared by coupling with inorganic Ag-loading SiO2 nanoantibacterial agent. The morphologies, structures and properties were characterized by using scanning electronic microscope (SEM) and differential thermal analyzer (TG-DTA), etc. The antibacterial and washing-fast performances were also tested. It showed that a compact antibacterial layer was formed on the surface of wool fiber and it possessed better mechanical and thermal properties. The efficiency of bacteriostasis action on E. coli and S. aureus is up to more than 96% and antibacterial efficiency is more than 90% after repeated washing (at least 30 times).