Abstract: Pre-planning a path is an effective way to reduce rescue response time and to keep the post-disaster traffic under control.In the paper,a heuristic path searching algorithm is suggested in order to efficiently preplan good candidate emergency path sets.Every alternative path calculated is checked under the conditions of constrains of both the reasonable path and the alternative path set constraints.The algorithm terminates when any of the alternative path constraints is satisfactory.Using the weight increment procedure,the reliability of the path set and the reliability of candidate paths within the set are increased efficiently.