Abstract: In order to reasonably set up the emergency bridging bus depots for urban rail transit under sudden incident, the bridging starting point was taken as the center of the circle, the operation recovery time of rail transit was taken as the radius, the bridging demand point reversely covered the emergency bridging bus supply point, and a cover structure was constructed. According to whether the bridging bus arrived at the bridging point before the scheduled departure time, the calculation methods of bridging demand and passenger waiting time delay were put forward. The reverse set coverage location model with an objective function of the minimum passenger total waiting time delay was established and solved. Taking a specific depot location for emergency bridging bus in rail transit as an example, the depot location schemes under differentnumbers of preset depots were analyzed and compared. Research result shows that the passenger total waiting time delay decreases with the increase of the number of preset depots. The objective function reaches the minimum when the number of preset depots is five. The depot location distribution is affected by the location of bridging starting point and bridging demand. When the number of preset depots is two, the depot location tends to gather at the center of the city. The depot locations tend to cover the suburb when the number of preset depots is five. After considering the impact of sudden incident weight, the depot location is close to the bridging point with high sudden incident frequency. Then, a balanced bus depot configuration inside and outside the center of the city can be formed. The reverse set coverage location model can minimize the passenger total waiting time delay of emergency bridging bus by active seeking supply, and can reflect the influences of the number of preset depots, passenger flow distribution of bridging starting point and sudden incident weight at the depot location for emergency bridging bus.