Cronobacter， a Gram-negative foodborne conditioned pathogen， is commonly found in both food and the natural environment， and causes neonatal necrotizing enterocolitis （NEC）， septicemia， and meningitis. The O antigen， which is the outermost structure of the lipopolysaccharide （LPS） in Gram-negative bacteria， serves as a crucial target for the host immune system. The genes responsible for synthesizing the O antigen are typically organized in clusters on the bacterial genome， known as O-antigen gene clusters （O-AGC）， and exhibit a high degree of specificity. The O antigen holds considerable importance in the identification and the serotyping of Gram-negative strains， exhibiting notable efficacy in epidemiological inquiry， disease prevention and control， as well as expedited detection. This article seeks to provide a comprehensive review of the recent advancements in O antigen typing of Cronobacter， examining its correlation with the O antigens of other Enterobacteriaceae. Additionally， the paper aims to explore the application and potential of O antigen， while summarizing the diverse characteristics of Cronobacter O antigen. It is hoped to facilitate further research on Cronobacter O antigen and enhance prevention and control measures for Cronobacter， thereby offering a valuable reference for food safety.