The theoretical study of objective determination methods for index weight and index attribution in evaluation of Metro operation safety can not meet the requirements nowadays. A fuzzy comprehensive evaluation model of Metro operation safety is established by entropy weight method and extensional theory. The index weight is calculated by weighted average of subjective weight and entropy weight, which can take full consideration of the experts’ decisions as well as the implication of the data. The degree of index attribution is calculated by the correlation function of the extensional theory. The fuzzy comprehensive evaluation method is verified by a case study of the Metro line in Beijing. The results show that the abovementioned model can evaluate the Metro operation safety effectively, improve the precision of index weight, accurately reflect the importance of every index and further improve the reliability of the evaluation results.