Cu/OMMT (organo-montmorillonite)/LLDPE (linear low-density polyethylene) nanocomposites were prepared via melt mixing combined with melt extruding process. X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra, scanning electron microscope (SEM), and transmission electron microscopy (TEM) were employed to characterize the resultant nanocomposites. The results showed that the OMMT layers were exfoliated and the nano-Cu particles were distributed uniformly in the polymer matrix. And the introduction of nanofiller into LLDPE matrix had little effect on the crystallinity of the polymer. The salt spray tests showed that OMMT and nano-Cu could improve the anticorrosion properties of LLDPE matrix, respectively. And the coexistence of OMMT and nano-Cu in Cu/OMMT/LLDPE nanocomposites could produce a synergistic effect on enhancing the anticorrosion properties. Furthermore, the co-incorporation of OMMT and nano-Cu into the polymer matrix also increased the thermal-oxidative stability and mechanical properties of LLDPE matrix significantly, as compared with the Cu/LLDPE and OMMT/LLDPE nanocomposites due to the synergistic effect. The bactericidal properties evaluation showed that the bactericidal ability of Cu/OMMT/LLDPE increases with nano-Cu content effectively.