Strengthening the promotion of coordinated development between regions and the optimization of spatial arrangement of city agglomeration network remains an important task of China’s development of economic modernization. On the basis of Baidu search index of cities in the Changsha-Zhuzhou-Xiangtan Agglomeration in the years from 2015 to 2018, the model that calculate and analyze the city agglomeration network is constructed, the characteristics in its spatial and temporal changes is generalized and revealed . The result shows that: For a long time, in the Changsha-Zhuzhou-Xiangtan Agglomeration, the city cores of these three cities fail to occupy the high tiers, but Changsha, Zhuzhou, Hengyang and Yueyang, Changde form the top three tiers. The city agglomeration network has also experienced a structural change as its structure, which was originally characterized by “one core and one center” , is now upgraded with “one core and multiple centers”. The pillar of the Changsha-Zhuzhou-Xiangtan Agglomeration network has been converting from being centralized to being decentralized, and more and more city contact centers more than only one have appeared with “new cities” rising outside the city cores. In the pillar change of city agglomeration network, the contact between the cities in the Changsha-Zhuzhou-Xiangtan network is not only one-way and limited within its core development circle only, but the development and cooperation is multi-directional and multi-dimensional between multiple choices and cities; the common contact between cities is becoming more and more intense, and the overall city agglomeration network is developing a more virtuous, flexible structure.