Abstract: This study built a model on dynamic link travel time for evacuation route in an emergency of Olympic Games, and was based on analysis of existing models of link travel time functions, and the matching analysis between the conditions of fluid mechanics and the characteristic of evacuation traffic flow. The authors proposes the Dynamic Link Travel Time Model, by which travel time including the running time on non-congestion section of upstream and the delay time of downstream intersection can be estimated, and an example is then presented to test the accuracy of the model. This study is a base for dynamic route choice in an emergency of Olympic Games.