Abstract: Bacillus subtilis H19, which has the effect of inhibiting Vibrio parahaemolyticus, was selected as the research object. In order to further study the properties and activity of the bacteriocin produced by B. subtilis H19, the fermentation supernatant of B. subtilis H19 was purified by crude extraction, chromatography and HPLC. MALDI-TOF was used to identify the molecular weight of bacteriocin. Combined with the third generation molecular sequencing technology, the functional genes of B. subtilis H19 were annotated by COG database, GO database and KEGG metabolic pathway. The drug resistance genes were predicted by ARDB database. The bacteriocin synthesis gene cluster was analyzed by antiSMASH software. The results showed that the final purification of bacteriocin BH19 was 460.73 times, the specific activity reached 307692.31 AU/mg, and the molecular weight was 1042.00 Da. The total length of B. subtilis H19 genome was 3595203 bp. The gene function annotation found that B. subtilis H19 has a strong ability of amino acid and sugar transport and metabolism, and contains several key bacteriocin transporter ABC proteins. After analysis, there was no antibiotic resistance gene in the whole genome, and a total of six bacteriocin synthesis gene clusters were obtained. Gene cluster 2 was NRPS gene cluster with a molecular weight of 1036.34 Da, which was 99.46% similar to the results of mass spectrometry, and the homology between gene cluster 2 and surfactin produced by Bacillus amyloliquefaciens was low, which was 82.00%. In conclusion, bacteriocin BH19 may be a new type of bacteriocin produced by B. subtilis H19. This study provides a reference for the development and application of B. subtilis H19 and its bacteriocin BH19 in the field of natural preservatives.