Abstract: Jiangsu section of the Grand Canal is not only a key area for the cultural protection and inheritance of the Grand Canal, but also a red river to witness the revolutionary history of our Party and conserve national spirit. On the occasion of the 100th anniversary of the founding of the Communist Party of China, this study takes the core area of Jiangsu section of the Grand Canal as the research subject. Based on tourism network data, this paper constructs an evaluation model of the network heat of scenic spots, and uses the methods of trend surface, kernel density, GIS analysis technology to explore the spatial-temporal evolution characteristics of the network heat of red tourism. The research results show as follows. (1) In terms of time evolution, the popularity of the red tourism network in Jiangsu section of the Grand Canal shows an evolutionary path of steady rise. The seasonal network heat shows a fluctuating trend of “three peaks and four valleys”, and the seasonal change of red theme heat is affected by the occurrence time of red events. (2) In terms of spatial evolution characteristics, the core of the red tourism network in Jiangsu section of the Grand Canal has evolved from “single core” to “three cores”, and the radiation of the high-density area of the red tourism network to the surrounding areas is increasing. In Southern Jiangsu-Northern Jiangsu-Central Jiangsu, the heat degree shows a decreasing trend. The degree of homogeneity of the red tourism network along the Jiangsu section of the Grand Canal is relatively poor, and the development speed of red tourism is fast in the southeast and slow in the northwest. (3) The development of red tourism in Jiangsu section of the Grand Canal is influenced by the regional policy support, the level of economic development and the construction of smart tourism. The integration of cross-city cultural and tourism exchanges plays a role in promoting its development. The epidemic situation has a certain impact on red tourism, but the change of tourists’ tourism preference brings a turning point for more less well-known scenic spots.