S. aureus has a high detection rate in fresh pork， which is one of the main foodborne pathogens that pollute fresh pork， and poses a great threat to food safety and human health. In this study， Congo red Agar method was used to determine the quality， 96-well microplate quantitative analysis combined with scanning electron microscope to detect the film-forming ability， PCR method was used to detect the film-forming genes and adhesion genes. Finally， the isolates were analyzed by multi-site sequence typing (MLST). The results showed that the qualitative test of Congo red Agar method showed that 84.93% (62/73) of the strains were biofilm positive， and the 96-well microplate quantitative test showed that 94.52% (69/73) of the strains were biofilm positive. Scanning electron microscope showed that the strains with different adhesion ability were enriched in gradient on the steel plate. PCR test found that all the strains contained multiple adhesion genes， which carried icaD， clfA， clfB， fnbA and fnbB at the same time. The strains of icaD， clfA， clfB， fnbA， fnbB， cna； icaA， icaD， clfA， clfB， fnbA， fnbB and cna had the largest number of multiple adhesion genes， which were 30.14% (22/73)， 20.55% (15/73) and 15.07% (11/73)， respectively. In MLST test， 73 strains were divided into 26 ST types， 20 in summer and 12 in winter. CC1 and CC5 were dominant clones in summer and CC15， CC1 and CC5 were dominant in winter. In the phylogenetic tree， the isolates were correlated with domestic food， iatrogenic and animal isolates， showing genetic diversity. The results can provide a scientific basis for the safety supervision of fresh pork， the transmission and the traceability investigation of S. aureus.