Abstract: The establishment of an integrated emergency-defense system is an important part of enhancing the national strategic capabilities of integration. The social network analysis method was used in this study. The integrated emergency-defense system collaborative network map was drawn from the perspective of the inter-ministerial horizontal coordination mechanism. Based on the "Core Degree Percentage-Limitation Percentage Ranking" two-dimensional framework, the evolution of cooperation network, organization role and interaction between organizations, as well as the evolution logic of collaboration network, were analyzed from the time dimension. The results show that China's integrated emergency-defense cooperation network presents an evolutionary model in which the overall structure is continuously optimized and the core institutions are promoted. The gradual integration and improvement of the network functions in the network promotes the continuous optimization of the overall network structure. At the same time, the core institutions in China's emergency-defense cooperation network have formed a transition process from "diverse weak core" to "stable strong core". The emergency-defense system has also been transformed from a single crisis event or a single disaster-oriented feature to co-ordination, multi-crisis events and multi-hazard coupling emergency-defense mode. In terms of network evolution logic, China's emergency-defense system presents a two-way driving model driven by institutional reform and national crisis management needs. On this basis, relevant recommendations were proposed from the "management system", "power construction", and "resource sharing" of China's integrated emergency-defense system construction.