Abstract: Earthquakes seriously threatened the safety of the people and affected the stable development of the whole society. In the face of complex and highly uncertain earthquakes, the rapid and effective implementation of emergency medical rescue is the most important way to save lives and reduce losses after the earthquake. The arrangement of emergency medical rescue process and the allocation of rescue resources are directly related to the efficiency of emergency medical rescue. The normal process of emergency medical rescue after earthquake was put forward through case analysis in this paper. Then the fuzzy stochastic Petri net model of the emergency medical rescue process was constructed by using the fuzzy stochastic Petri net theory. And according to the isomorphic relation between the fuzzy stochastic Petri net and the Markov chain, the system state of the steady-state probability of the expression could be derived, based on which key links could be found. On this basis, considering the relationship between the medical resources and rescue efficiency,the timeliness assessment function is adopted to evaluate the implementation efficiency of the key links, and the result that the same resource ratio has the optimal value was derivable from theory. Taking "Wenchuan earthquake" as an example, the changes of steady-state probability under different conditions were obtained by both dynamic and static analysis, and the key links of the emergency medical rescue process after earthquake were defined. In the rescue process, the input amount of resources was taken as independent variable, and the optimal resource ratio of the key link in the case of fixed medical resources was obtained by numerical simulation.Accordingly, corresponding countermeasures and suggestions for emergency medical rescue after earthquake were presented, which could improve the efficiency of emergency medical rescue and provide decision support for the deployment of emergency medical rescue for earthquake disaster.

Key words: earthquake, emergency medical, rescue process, fuzzy stochastic petri net, assessment function