Abstract: Pseudomonas aeruginosa is a multidrug-resistant bacterium that can cause a variety of diseases in poultry and livestock, and its outer membrane permeability is much lower than that of other bacillaceae, which is an important reason for its drug resistance and clinical treatment failure. By testing the killing effect of carvacrol and gentamicin on Pseudomonas aeruginosa under different treatment conditions（including concentration, time and medium）, and evaluating the degree of damage to the cell membrane of Pseudomonas aeruginosa, the killing effect of carvacrol as an adjuvant against gentamicin PAO1 was further explored.The results showed that with the assistance of 0.01% carvacrol, the dosage of gentamicin could be reduced by 100 times, and the bactericidal effect of Pseudomonas aeruginosa could be significantly enhanced within 1 h. The auxiliary effect is adaptable to different media, and also has a certain broad-spectrum under different antibiotics, and can improve the killing effect of gentamicin on clinical Pseudomonas aeruginosa. The results of this study provide strong data support for the application of carvacrol as an antimicrobial adjuvant in reducing the resistance of Pseudomonas aeruginosa.