Terbium/zinc antibacterial silica gel was prepared by sol-gel method. The better preparation conditions were obtained by controlling single factor variable experiments: The concentration of zinc ion 0.8 mol·L-1，the rare earth terbium concentration 0.003 mol·L-1 and reaction time 1 h. And as-prepared materials were characterized by X-ray diffraction (XRD)，scanning electron microscopy (SEM)，X-ray photoelectron spectroscopy (XPS) andinductive coupled plasma emission spectrometer(ICP) analyses. The results showed that this antibacterial silica gel was amorphous，and its structure was fluffy and porous. The presence of homogeneously mixed zinc and terbium, in the form of ZnO and Tb2O3. The ICP analysis resulted in 1.82% of Zn and 0.073% of Tb Antibacterial test results showed that the material had an inhibitory effect on the growth rate of E.coli. The antibacterial rate of the material after adding rare earth terbium increased from 72% to 87%. Synergistic antibacterial effect of rare earth on materials was judged by synergistic effect factor (SEF) and synergy coefficient (T/E)，terbium was a synergistic antimicrobial agent in materials. The synergistic antimicrobial mechanism of rare earth was preliminarily analyzed through the results of the specific surface area, pore size and the loading capacity of zinc ions.