Cronobacter，a gram-negative foodborne conditioned pathogen，is commonly found in both food and the natural environment, and causes neonatal necrotizing enterocolitis, 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.