This study aims to examine the risk of each category of behavior related to different accident types and consequences by introducing the Monte Carlo algorithm. Totally about 234 cases were collected to construct a structured dataset, and 12 categories of passengers’ unsafe behaviors related to the four types of metro operation accidents including escalator injury, crowd stampede, pinched by a shielding barrier and fall injury were considered for this analysis. Results showed that although the total behavioral risk of each accident type obeys normal distribution with means between (4, 6] in the Moderate risk level, the variances of pinched by a shielding barrier (1.29) and crowded stampede (1.08) are much higher than escalator injury (0.60) and fall injury (0.59). The top four contributors that resulted in the accident behavioral risks were irregular behavior on the escalator, go on boarding even after the door-close alarm sounded, push each other, and pay no attention to the ground. It was concluded that due to the uncertainty of the behavior occurrence and its consequences, there are differences of the probabilities in different risk levels of the four accidents caused by the various passengers’ unsafe behaviors. Based on the results, risk mitigation measures for different accident types are recommended. This paper provides a quantitative method to compare and analyze the effect of passengers’ unsafe behaviors related to different accident types and severities, which has relative comparative significance and improves the accuracy of judging the probability distribution of risk degree that can provide basis for risk mitigation in metro operation.