Abstract: In order to reduce the impact of the fire evolution process of urban complex buildings, the chain-styled theory of disaster and complex network theory were identified for expressing the accident. The network models of fire disaster chains evolution of urban complex was established from the hazard factors, the disaster-pregnant environment, the hazard bearing body and other factors. Then, the risk analysis was carried out by the out-in degree, the number of subnet nodes, the betweenness centrality and other indicators during the disaster evolution. Comprehensively evaluate the importance of the network nodes and the vulnerability of the edges of the disaster chain, we can get the key nodes that affect the disaster and the location of the broken chain. This analysis provides references for mitigating disasters caused by fires in complex buildings. It is concluded that, the more vulnerable edges in the disaster chain have a certain correlation with the more important nodes. During the evolution of urban complex building fires, traffic tie-up, crowds panic, damaged overpasses, damaged subway station and explosion are the key nodes of risk control.

Key words:  urban complex, fire disaster chain, complex network, vulnerability, risk assessment