() is well-known to cause biofilm-associated drug resistance and infections that often lead to treatment failure. Herein, we reported a dual-acting antibiofilm strategy by inhibiting both the bacterial quorum sensing system and the iron uptake system. A series of coumarin derivatives were synthesized and evaluated, and compound was identified as the most effective biofilm inhibitor (IC = 3.6 μM). Further mechanistic studies have confirmed that not only inhibits the QS systems but also competes strongly with pyoverdine as an iron chelator, causing an iron deficiency in . Additionally, significantly improved the synergistic antibacterial effects of ciprofloxacin and tobramycin by more than 200-1000-fold compared to the single-dose antibiotic treatments. Therefore, our study has shown that is a potentially novel antibacterial synergist candidate to treat bacterial infections.