Benzo[a]pyrene (BaP), a high-molecular-weight PAH, exhibits strong recalcitrance to microbial degradation and high biotoxicity. In this study, two root exudate derivatives, sodium palmitate (SP) and sodium linoleate (SL), were employed as biostimulants to explore their regulatory mechanisms on BaP degradation by a bacterial consortium (BC). Results showed that both SP and SL significantly reduced surface tension and accelerated BaP degradation, with SL exerting a more pronounced effect. This enhancement was attributed to their roles in not only improving BaP bioavailability but also promoting the biosynthesis of extracellular polymeric substances (EPS) and lipopolysaccharides (LPS). Microscopic morphological and transcriptomic analyses revealed that both SP and SL protected cell integrity by upregulating cell wall and peptidoglycan synthesis genes, and comprehensively activated genes involved in aromatic ring degradation (e.g. catE、ndoA、pcaG) and fatty acid metabolism (e.g. alkM、fabY、fadB). Specifically, Achromobacter and Brucella dominated the significant upregulation of key BaP ring-opening genes (catE, ndoA, pcaG); in contrast, Achromobacter, Alcanivorax, and Isoalcanivorax primarily contributed functional genes related to downstream benzoate degradation and EPS/LPS biosynthesis. Soil microcosm experiments verified that the BC_SL combination achieved optimal PAH degradation efficiency by enhancing the colonization and proliferation of exogenous functional strains, as well as the selective enrichment of indigenous PAH-degrading microorganisms in soil. Collectively, this study elucidates the micro-mechanisms of sodium fatty acids in enhancing BaP degradation, providing theoretical support for the practical bioremediation of contaminated soils.