Nerol subinhibitory concentrations block A. baumannii quorum sensing, inhibiting AHL, biofilm formation, motility, and EPS production. Proteomics validated these phenotypes, showing synchronous downregulation of key virulence proteins including BfmS and MacB. ITC confirmed its binding to BfmS disrupts the BfmRS two-component system. In a mouse pneumonia model, it significantly reduced lung bacterial load, blocked the NF-κB/MAPK axis, decreased inflammatory expression, restored lung tissue structure, and showed no hepatotoxicity. This provides a safe, non-antibiotic strategy for treating carbapenem-resistant Acinetobacter baumannii pneumonia.