Objective To conduct an epidemiological investigation on a foodborne disease outbreak caused by consuming beef contaminated with Xylazine during a collective dinner， analyze the causes of contamination， provide reference for handling similar incidents in the future， and provide a basis for proposing targeted prevention and control measures.Methods According to the “Technical Guidelines for Epidemiological Investigation of Food Safety Accidents （2012 Edition）”， a population epidemiological investigation， food hygiene investigation， and laboratory testing were conducted on a suspected foodborne disease outbreak that occurred in a catering service unit in a certain area. Descriptive epidemiology and analytical epidemiology methods were used to organize and analyze the data. EpiInfo 7.1 software was used for chi square test and multivariate logistic regression analysis， and P<0.05 was considered statistically significant.Results As a result， there were a total of 27 cases in this incident， with an incidence rate of 47.37% （27/57）. The main clinical manifestations are dizziness （100.0%）， drowsiness （37.0%）， and bradycardia （37.0%）； The epidemic curve shows point source exposure， and the results of univariate （OR=29.71， 95% CI： 3.56-248.10） and multivariate logistic regression （OR=16.577， 95% CI： 1.307-210.055） studies indicate that the suspicious food is spiced beef； The results of the food hygiene investigation showed that the contamination process was due to the failure to meet the requirements of the veterinary drug rest period， as well as the unauthorized slaughter and excessive slaughter， resulting in raw material contamination； Xylazine was detected in biological specimens， semi-finished food products， retained food samples， and processing environment samples of the cases.Conclusion This incident is a foodborne disease outbreak caused by the consumption of spiced beef contaminated with Xylazine. It is suggested to further increase the training efforts for the “Pharmacopoeia of the People’s Republic of China for Veterinary Drugs” and improve the training effectiveness； Strengthen the supervision of the use of veterinary drugs and strictly implement the regulations on the withdrawal period； Strengthen slaughter supervision and crack down on illegal and indiscriminate slaughter； Further improve the harmless treatment of dead livestock and poultry； Strengthen supervision over the use of veterinary drugs， crack down on illegal slaughtering， and implement the system of obtaining tickets and certificates for raw materials.