Under the influence of tourism and globalization, heritage production presents a new landscape. As a crucial framework for interpreting heritage, Authorized Heritage Discourse (AHD) has profound significance in discussing its practice characteristics in this context. Taking cities along the Jiangsu–Zhejiang section of the Grand Canal as a case study and drawing upon policy text, this study explores the practice characteristics of AHD in the tourism context. Results indicate that the thematic practices of AHD encompass protection and management, ecological construction, cultural production and inheritance, touristification, infrastructure and services, and marketing and cooperation, forming a clustering pattern with touristification as the central theme. The spatial characteristics manifest as multi-scale practices ranging from global to regional to local, each corresponding to diverse thematic characteristics. This study deepens the understanding of AHD in tourism and advances the research progress of heritage tourism. It also provides practical references for the utilization of urban heritage and the management of heritage tourism.