With the continuous adjustment of regional development patterns,city clusters have become the core carrier of China's regional eco-nomic layout.The Chengdu-Chongqing city cluster is one of the 19 city clusters in the national 14th Five-Year Plan,with a unique and important strategic position as it is a component of China's national urbanization strategic layout featuring"two horizontal and three ver-tical axes"and the connection point of the Yangtze River Economic Belt and the Belt and Road Initiative.Specifically,the two horizontal axes involve urbanized areas along the Eurasian Land-Bridge(China section)and the Yangtze River Belt,and the three vertical axes re-fer to urbanized areas along the coastal China,the Harbin-Beijing-Guangzhou Railway,and the Baotou-Kunming Railway.