Abstract
Based on the cellular automaton principle and multi-agents theory of complex systems, this essay studied the public health unconventional emergencies generation and evolution mechanism, established evolution model and carried out simulation of the public health unconventional emergencies evolution mechanism, and finally took SARS emergency for an example. Research results showed that the evolution of the public health emergency often promots other linkage emergencies, the damage of linkage system is larger than that of promotion system, and the damage is uncontrolled except for controlling the promotion system effectively, just like isolation measures or inject vaccine for individual of the promotion system so as to prevent promotion system from producing linkage hazards.