Objective To investigate and trace the source of Salmonella enteritidis food poisoning in a welfare institution, so as to provide reference for the study of similar foodborne disease. Methods Epidemiology, food hygiene and pulsed field gel electrophoresis (PFGE) technology were used to investigate and analyze the incident. Results There were 23 confirmed cases of foodborne disease, and the incidence rate was 5.65% (23/407); 15 anal swabs were collected from patients, as well as 3 anal swabs from kitchen staff, 3 preserved dishes, 2 fruits and 1 cold drink. Salmonella enteritidis was detected from 11 anal swabs. PFGE typing result showed that the similarity of 11 strains of Salmonella enteritidis was 96.4%, and cluster analysis showed that they were the same type. It was preliminarily determined that the strain was from the same clone line. Conclusion Based on the analysis of epidemiology, food hygiene and laboratory test result, it was confirmed that the foodborne disease was caused by Salmonella enteritidis. Welfare institutions should strengthen the management of food safety for special groups, and formulate corresponding emergency response plans for food poisoning emergencies to prevent the recurrence of such accidents.