In this paper, a deaggregation technology and its mechanism were studied for the Ag/ZnO nanocomposite antibacterial agent added with PVPK17 by sedimentation experiment, laser scattering particle size analysis and transmission electron microscopy (TEM). The minimum inhibitory concentration of the fore-aft deaggregation Ag/ZnO nanocomposite antibacterial agent was tested. The results showed that the Ag/ZnO nanocomposite antibacterial agent in isopropanol could be stable suspension more than 6 days after deaggregation with PVPk17, the average particle size was smaller than 51.3 nm. The dispersion effect was the best when the mass % of PVPk17 was 40%. TEM results show that the Ag/ZnO nanocomposite antibacterial agent is kindly dispersed. Then, a model of deaggregation mechanism was built. The MIC of Ag/ZnO nanocomposite antibacterial agent was 50 mg/L after deaggregation, with good antibacterial property