In order to improve the reliability and risk resistance of the express delivery network, the article constructs a basic model of the express delivery network from the perspective of multimodal transportation. At the same time, considering the possible hub failure problem of the hub and spoke express delivery network, the optimal backup node is selected for the hub node, and a backup hub model for express delivery network design is proposed. Study the changes in network structure, total cost, and express handling volume of hub nodes after hub failure, and analyze the impact on adjacent hubs and paths. Case analysis shows that the failure of hub nodes can cause changes in the characteristics of express delivery networks, transportation routes, and transportation modes; Enabling a backup hub will lead to an increase in the express handling volume of hub nodes, increasing the pressure on the hub to handle express delivery and potentially causing congestion in the backup hub.