Bacteria secrete exosomes containing stress-related molecules such as proteins and nucleic acids, which facilitate adaptation to challenging environments. In order to elucidate the role of A. acidoterrestris exosomes in its acid stress response, this study combined proteomics and metabolomics to analyze the function and biological pathway of exosomes in A. acidoterrestris against acid stress The results of exosome proteomics showed that spore coat protein D, SecA, YidC, chemotactic protein CheA, methyl-accepting chemotactic protein (MCP), serine-type D-alanine-D-alanine carboxypeptidase protein, and lipid II glutamine synthetase subunit GatD protein were significantly up-regulated. These proteins are mainly enriched in ABC transporters, two-component systems, quorum sensing, peptidoglycan biosynthesis and other pathways. The results of exosomal metabolomics showed that 83 and 68 differential metabolites were detected in positive and negative ion modes, respectively. These metabolites were mainly enriched in ABC transporters, carbohydrate metabolism and amino acid metabolism. This study showed that the exosome proteins and metabolites secreted by A. acidoterrestris under acid stress changed significantly, revealing the overall response of A. acidoterrestris to acid stress, and pointing out the possible future direction for the effective control and application of A. acidoterrestris