In this study， quorum-sensing quenching activity of Lactobacillus crustorum ZHG2-1 was verified with the Chromobacterium violaceum CV026 as a indicator strain. Based on the change of biofilm， phenotypes of spoilage factors and the expression levels of related genes， the quorum sensing quenching mechanism of Lb. crustorum ZHG2-1 on P. fluorescens was detected. The results showed that the degradation rate of cell-free supernatant from strain ZHG2-1 to P. fluorescens AHLs reached 100%. The sub-inhibitory concentration (1.0， 2.0， 3.0 mg/mL) of strain ZHG2-1 crude extract could inhibit and remove the biofilm of P. fluorescens, and the inhibition rate and clearance rate reached 9.66%-31.32% and 28.62%-62.82%, respectively. In addition, the inhibition rate of strain ZHG2-1 crude extract with sub-inhibitory concentration on P. fluorescens spoilage factors (exopolysaccharides， proteases， lipases， biogenic amines) reached 7.23%-100%. Meanwhile， the inhibition rate was mass concentration-dependent. Scanning electron microscope showed that the sub-inhibitory concentration of strain ZHG2-1 crude extract treatment significantly reduced the amount of biofilm and the bacterial colonies were in a dispersed state. The results of qRT-PCR showed that the crude extract of strain ZHG2-1 down-regulated the quorum-sensing genes rhlI and rhlR of P. fluorescens by 0.93 and 0.99， respectively， and the expression levels of aprX， algA， orm， flgA， ldcA and other biofilm and spoilage genes was significantly inhibited. The results indicated that Lb. crustorum interfered with the expression of quorum-sensing genes of P. fluorescens， thereby affecting the production of biofilm and spoilage factors.