A relationship structural model about traffic and the city location strategy localization has been established in this paper, and also an algorithm of traffic condition change affecting the city radiation scope and a decision program of the city location strategy localization are set up. The author thus supplements and develops the breaking point theory, and provides scientific basis for positioning of many cities in China. At last, taking Chongqing city as an example, the paper analyzes the localization strategy of Chongqing city under the new traffic environment.