The work aims to study the optimum technological conditions and antibacterial properties of nano-ZnO particles prepared by hydrothermal synthesis, with zinc acetate and sodium hydroxide as raw materials. The particle size and morphology of nano-ZnO particles were used as evaluation indicators to discuss the influence of synthesis conditions on the product. Based on the single-factor design response surface experiment, with the diameter of the inhibition zone as the response value, the preparation conditions of nano-ZnO particles with good antibacterial effect were analyzed. The nano-ZnO particles prepared under the following conditions had the best antibacterial effect: the hydrothermal temperature of 111.14 ℃, the reaction time of 10 h, and the concentration of zinc acetate of 0.02 mol/L. The inhibition zone diameter of escherichia coli was (17.265±0.011) mm. The hydrothermal temperature, hydrothermal time and precursor concentration affect the particle size and morphology of nano-ZnO particles. Hydrothermal temperature and precursor concentration are significant factors affecting the antibacterial activity of nano-ZnO particles. Hydrothermal time is not a significant factor.