Objective: Pseudomona aeruginosa biofilm (BF) is a major cause of persistent food contamination. Nisin， a natural food preservative， can inhibit a variety of foodborne pathogens， but is ineffective against Gram-negative bacteria. In this study， it aimed to enhance the inhibition and BF scavenging ability of P. aeruginosa ATCC 9027 biofilm by combining Nisin with honokiol， and to investigate the related mechanism of action. Methods: Firstly， this study screened the herbal components that could inhibit P. aeruginosa BF and the minimum inhibitory concentrations； then this study evaluated the synergistic inhibitory effects of Nisin in combination with honokiol on the biofilm of P. aeruginosa， the changes of the inhibitory effects over time， and the effects on the structure， components and related gene expression of BF. Results: The strongest inhibitory effect of honokiol on the biofilm of P. aeruginosa ATCC 9027 was selected as the herbal component in combination with Nisin； the MBIC50 of Nisin and honokiol were 1 mg/mL and 12.5 μg/mL， respectively. several combinations showed synergistic inhibitory effects， among which 1.5625 μg/mL of honokiol and 0.125 mg/mL Nisin had the best synergistic inhibition effect on BF， reaching the highest at 18 h. Moreover， the combination of the two significantly affected the structure of BF and reduced the content of extracellular polysaccharide and eDNA， while the expression of BF-related genes lasR， pelA， algC， pqsA and lasI was reduced. Conclusion: The combination of Nisin and honokiol phenol has a synergistic effect on the biofilm of P. aeruginosa ATCC9027， which can reduce the transcription level of BF-related genes to decrease the secretion of EPS and eDNA， thus inhibiting and scavenging BF.