Abstract: Using Yunyan 87 as the test tobacco variety, a pot experiment was conducted to study the effects of a foliar spray mixture of of haloxyfop-P-methyl, quizalofop-P-ethyl, and fenoxaprop-P-ethyl on tobacco growth and their degradation dynamics in tobacco leaves. After the application of the three herbicides during the seedling or vigorous growth stages, the agronomic traits related to tobacco growth were not inhibited, and no significant differences were found in chlorophyll content, or key chemical components of the tobacco leaves, compared to the blank control group (p>0.05). A method for simultaneously detecting the residues of the three herbicides in tobacco leaves using HPLC-HRMS was established. At the spike levels of 0.02, 0.2, 2, and 20 mg/kg, the recoveries of the three herbicides in the tobacco leaf matrix ranged from 85.09% to 104.73%, with intraday (n = 5) and interday (n = 15) relative standard deviations less than 11.29%. At 2 hours after application, the initial residues of haloxyfop-P-methyl, quizalofop-P-ethyl, and fenoxaprop-P-ethyl in tobacco leaves were 9.44, 7.90, and 9.78 mg/kg, respectively. The half-lives of the three herbicides in tobacco leaves were 10.66, 21.00, and 16.50 days, respectively. This study provides a reference method for the simultaneous detection of three herbicides in tobacco and offers a theoretical basis for the scientific application of herbicides to ensure safe tobacco production.