Lingqu Canal bridges the Yangtze and Pearl River water systems and plays an important role in the great unification process of ancient China. Previous studies emphasize the Qin and Han dynasties over later generations, ignoring the complex historical picture of the relationship between the existence of Lingqu Canal for more than two thousand years and regional socio-economic development, ethnic interaction, and the shaping of dynastic orthodoxy. From Lingqu to Douhe, and then to Eastern and Western Douhe, the functions of Lingqu Canal gradually increased and played a corresponding role in the various stages of the process of the great unification of ancient China. Since the 12th century, the integration of the water conservancy system in northeastern Guangxi by the state in Qing Dynasty, in particular, laid the material base for the communication between the southwestern provinces and other regions in the central and eastern parts of the country. In terms of dynastic border strategy, the linkage of Eastern and Western Douhe enhanced the central government's ability to control the provinces of Guangxi, Yunan and Guizhou. In terms of the regional market, with the convenience provided by Lingqu Canal, the inter-regional rice and salt trade between Hunan, Guangdong and Guangxi has developed significantly, and the inter-regional rice and salt trade, which lasted for hundreds of years, has also provided favorable conditions for the economic development along Lingqu Canal. For the northern part of Guangxi, the development of the irrigation function of Lingqu Canal has promoted agricultural development in the region. At the same time, with the further development of northeastern Guangxi and the commercialization of mountain forest products, Lingqu Canal became an important commercial route for the transportation of local products such as timber and tea. The surrounding ethnic groups were gradually incorporated into a unified market system, and the ethnic relation ushered in a new historical stage. Since the 12th century, under the joint management of the government and the private sector, the temples around Lingqu Canal have strengthened themselves by absorbing other beliefs, forming three groups of shrines and temples. Between the three, especially Lingji Temple and Longwang Temple, has gradually reached a certain equilibrium in competition. The construction of temples not only reflected the promotion of official ideology and the shaping of political identity, but also intensively displayed a historical picture of the blending of local multicultural traditions. Northeastern Guangxi and even Lingnan region, where Lingqu Canal is located, were taking unification as the greatest from below. Lingqu Canal has a long and profound influence on the great unification of China.