Microbiologically influenced corrosion (MIC) of engineering structures poses significant safety risks, particularly in environments where sulfate-reducing bacteria (SRB) are prevalent. In this study, a highly stable hydrosol with strong antibacterial properties is developed by adsorbing hydrophilic groups of polymer chains onto the Cu-Ag bimetallic nanoparticles (BNPs). The synergistic effects of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) overcame the incompatibility between the polymer components and nanomaterials, enhancing the dispersion and stability of the Cu-Ag BNP hydrosol. The results demonstrates that the hydrosol exhibited potent antibacterial activities at 50 ppm (w/w), achieving approximately a 5-log reduction for sessile cells after 21 days using retrieved coupons from 3-day pre-culture vials. The hydrosol led to much cleaner X80 coupon surfaces due to biofilm inhibition and MIC mitigation. The weight loss measurements reveals corrosion inhibition efficiencies of 91% and 78% at 50 ppm and 25 ppm, respectively. Additionally, the density functional theory (DFT) modeling reveals that copper regulates silver ion release, enhancing the antibacterial action. While the Cu-Ag BNP hydrosol shows great potential, challenges still exist in scaling its applications, especially in marine and other harsh environmental settings. This research provides a promising platform for developing sustainable bacterial control strategies, suppressing SRB growth.