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Objective To find out the causes and risk factors of this food-borne disease outbreak that occurred in November 2019 at four schools in Qinzhou, Guangxi, implement effective preventive and control measures to curb the spread and escalation of the outbreak, and provide a basis for the investigation and management of similar incidents in the future. Methods Descriptive epidemiological methods were used to analyze the cases' clinical characteristics, three-dimensional distribution, and related risk factors. The etiological food was determined by the method of analytical epidemiology. A food hygiene investigation was conducted to trace the process of food contamination, and biological samples from cases and workers, suspicious food, and environmental samples were collected for laboratory testing. The detected Salmonella strains were analyzed for homogeneity using pulsed-field gel electrophoresis (PFGE). Results The event involved four schools, with 69 suspected cases identified, resulting inan attack rate of 0.52% (69/13 307). The main clinical symptoms were abdominal pain, diarrhea, and fever, with an average incubation period of 20 hours. The epidemic curve indicated a point-source outbreak. Descriptive epidemiological methods inferred that bakery products distributed by Company F were the suspect foods. The case-control study indicated the risk of illness was increased among those who purchased and consumed food supplied by Company F (OR=37.67, 95%CI: 14.03-101.13), particularly those who consumed the delicious hamburger (OR=30.13, 95%CI: 13.22-68.67). Salmonella Enteritidis (SE) was detected in 12 anal swabsfrom patients, one patient's vomit, one flour sample used for bread-making, and one egg, with homogeneity of 100% achieved in PFGE molecular typing of the 15 positive Salmonella strains. Conclusions The outbreak is a food-borne disease outbreak caused by Salmonella contamination. It is recommended that regulatory authorities strengthen supervision and management of production and processing enterprises, standardize food processing processes, and establish and improve food safety management systems and long-term mechanisms for food safety knowledge promotion and education in schools to enhance students' hygiene awarenessand prevent similar incidents from occurring. [ABSTRACT FROM AUTHOR]