［Objective］The purpose of this study was to develop efficient antibacterial waterborneinterior wall coatings. By using self-made KH550 surface modified silver nanoparticles（AgNPs）as an antibacterial agent，a coatings product with excellent antibacterial properties was successfully prepared.［Methods］ Using silver nitrate aqueous solution as silver source，γ -aminopropyltriethoxysilane（KH550）as surface modifier，1，2-propylene glycol as solvent and reducing agent，KH550 surface modified silver nanoparticles（AgNPs） were prepared by solution chemical method. During the experiment，AgNPs were successfully synthesized using 1，2-propanediol as solvent and reducingagent，and 0. 1 mol/L silver nitrate aqueous solution as silver source. Subsequently，different proportions of AgNPs dispersion were added to the waterborne coatings，and the antibacterial coatings were cured by volatile solvents. The optical properties，chemical composition and morphology of AgNPswere characterized by ultraviolet-visible absorption spectroscopy（UV-Vis），X-ray photoelectron spectroscopy（XPS）and transmission electron microscopy（TEM），and the antibacterial properties of the coatings were systematically evaluated.［Results］ AgNPs exhibited excellent antibacterial properties against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. When the addition amount of AgNPs dispersion reached 1. 05%，the antibacterial rate of the antibacterial coatings against Escherichia coli reached 100%，and the antibacterial rate against Staphylococcus aureus reached 99. 1%.［Conclusion］In this study，high-efficiency antibacterial waterborne interior wall coatings was successfully prepared by KH550 surface-modified AgNPS. The antibacterial performance was positively correlated with the amount of AgNPS added. The broad-spectrum antibacterial effect couldbe achieved at the addition amount of 1. 05%，which provided a feasible solution for the antibacterial functionalization of architectural coatings.