Abstract: 289 prefecture-level and above cities in mainland China were selected as the research object, and Baidu index data of each city was collected. Graphical discriminant analysis and cluster analysis were used to discriminate the hierarchical structure of China's urban system. 3 national central cities, 13 regional center cities, 22 provincial center cities and 251 local center cities were celected. This research showed that the hierarchical pyramid pyramid structure of Chinese cities under the information network was already obvious; the rank of cities was significantly affected by social economy, tourism culture and hot events; the distribution of high-grade cities was presented of a "Eastern and southern dense,Western and northern sparse" state, which was consistented with the distribution pattern of urban groups.