Abstract: Subway security is normally faced with the trade-off between safety and efficiency.There are two typical security modes. One is to install a face capture system at the entrance of a subway station to track, interrogate or capture potential terrorists (IFR), the other is to intercept contraband through checkpoints, and that is a way of upgrading the original security inspection equipment (USE). However, there are great differences between the two strategies in terms of security resource allocation, detection object, passenger traffic speed, passenger congestion in security inspection hall and train waiting hall. From the perspective of operational profit demand, the resource of terrorist defense is usually limited, in other words, the security department is faced with an either-or situation. A sequential game model of subway terrorist defense strategy selection is constructed under the constraint of limited resources, based on the target value dependence of terrorist decision-making and the asymmetric response time of the patrolmen.Firstly, the process models of the two security modes are described; Secondly, six equilibrium scenarios of four decision-making combinations are obtained and analyzed; Thirdly, the passenger congestion model of the security inspection hall and waiting hall which can reflect the passenger traffic speed is described, and the impact effect of the peak passenger flow on the decision-making of both sides is further analyzed; Finally, some suggestions on the selection of terrorist defense strategies are given combined with a case. It is found finds that when the accuracy of the enhanced security system, or the effective efficiency of the response time of the patrolmen is higher than a certain threshold value, the IFR strategy is dominant, and the social value of the face recognition system has no direct impact on the decision-making. When the accuracy of enhanced security inspection system is moderate, or the effective efficiency of response time of the patrolmen is lower than a certain threshold value, in the first case, when security department focuses on efficiency, the social value of face recognition system is positively correlated with security efficiency, and the IFR strategy is dominant when its social value is higher than a certain threshold value; In the second case, the USE strategy is dominant when the security department focuses on safety, at this time, the social value of the face capture system has no impact on the decision-making of the security department. In addition, a higher security inspection accuracy rate will enhance the passenger congestion level of the security inspection hall, strengthen the impact effect of peak passenger flow on the security inspection hall, weaken the impact effect of peak large passenger flow on the waiting hall, and ultimately increase the risk of terrorist attacks on the security inspection hall.In case selection, this paper selects Jishuitan station of Beijing Metro Line 2 as the case study object. In other key parameters, this paper takes the relevant authoritative research as a reference.In this study, a valuable security inspection process model and a passenger congestion prediction model are provides; Furthermore, the allocation of conventional security resources should be fully combined with the impact period under the two security modes is suggested, when considering the impact of high peak passenger flow.

Key words: subway anti-terrorism; sequential game; subway security inspection; face recognition system; passenger congestion