To analyze the inhibitory effect of Aspergillus flavus on the metabolism of Lactiplantibacillus plantarum P9 under co cultivation， this study co cultured L. plantarum P9 with A. flavus. The differences in viable counts between L. plantarum P9 monoculture and co-culture were analyzed， and based on the differences in viable counts， samples were taken at 9 h and 13 h of co-culture for non-targeted metabolomic analysis， and the enrichment of differential metabolites and their pathways at the sampling sites were investigated. The results showed that L. plantarum P9 could significantly inhibit A. flavus， and the differential metabolites produced by co-culture were mainly in the energy metabolism pathway， including: glycolysis/gluconeogenesis pathway， citric acid cycle， pyruvate metabolism pathway， amino acid metabolism pathway， folate biosynthesis pathway and organic acid metabolism pathway. In comparison with the reported inhibition substances produced by L. plantarum， the identified differential metabolites that may play an antagonistic role against A. flavus are mainly organic acids such as 2-amino-3-hydroxybutyric acid， hexadecanoic acid， 2，3-dihydroxybenzoic acid， and amino acid substances such as bacillus peptides， and this study provides a reference for further research on the inhibition substances of A. flavus by L. plantarum.