Complex network theory is used to study various complex systems in the real world, and it is widely used in many important fields such as computers, social, biology and transportation. In order to ensure the safety performance of the logistics network in Northwest China, this paper takes the postal logistics activities of 25 cities in Northwest China as the basis, establishes the macro logistics network between cities by counting the postal material flow of each city, establishes the micro logistics network within the cities by crawling the storage centers, distribution centers, and business outlets within cities through the Gaode map, and then combines the two in order to construct the semi-macro Logistics network. Analyze the characteristics of the logistics network, determine the importance of the nodes of the logistics network, and then study the robustness of the logistics network through different attack strategies. Theoretical and simulation analyses show that a single index such as degree or median cannot be used to measure the important nodes in the network, and that deliberate attacks make the vulnerability of the logistics network more obvious when cascading failures are considered.