Abstract: To screen effective prevention and control methods for tobacco wilt disease, a pot experiment was conducted to determine the prevention and control effect of eugenol on wilt disease, and the changes in tobacco physiological and biochemical indices, defense related substances, and enzyme activity were detected. The results showed that pre-treatment of 1 μL/mL eugenol for 3 days and inoculation with Ralstonia solani obtained control effect of 53.46% against Ralstonia solani after 15 days of inoculation. The treatment of 1 μ L/mL eugenol improved growth of tobacco, with the leaf length, leaf width, plant height, and stem circumference increased by 48.80%, 35.06%, 22.44%, and 8.98%, respectively, meanwhile the content of chlorophyll a, b, and carotenoids increased by 48.06%, 47.17%, and 77.87%, respectively, the root vitality, NR, POD, SOD, PPO, and PAL enzyme activities increased by 49.25%, 65.42%, 123.44%, 46.89%, 104.20%, and 46.89%, respectively, while the contents of MDA and H₂O₂ decreased by 30.43% and 55.58%, respectively. It is concluded that 1 μL/mL eugenol can improve tobacco plant growth, and effectively induce tobacco resistance to bacterial wilt, which provides a new source for novel biological pesticides to prevent and control bacterial wilt.