The integration of digital media art into the public art design of the smart city can enhance people’s participation and sense of identity in the art design of public space and maximize the attractiveness and cultural connotation of the city itself. Based on this, this paper builds a fusion technology framework mainly based on digital projection technology and digital interaction technology, proposes an interactive projection technology integrating digital projection and Kinect, and combines the dynamic scene image splicing and alignment fusion technology to realize the interaction between the user and the digital scene. In the case analysis of Qianjiang New City, the number of visitors reached 31.55 million in 2022. The evaluation score of landscape facilities in the public evaluation of architectural landscape is under 3.5. The overall evaluation grade is only “general,” and the evaluation mean value of the degree of intelligence of landscape facilities is only 3.089. The comprehensive evaluation satisfaction of the digital landscape includes multimedia landscape, architectural landscape, and landscape facilities, and the average value of the evaluation of the degree of intelligence of the landscape facilities is only 3.089. The satisfaction value of the multimedia landscape, landscape of buildings and structures, and water landscape in the evaluation of satisfaction is 4.36, 4.159, and 4.027, respectively, which reaches the level of “good” satisfaction, while the satisfaction value of landscape facilities is 3.479, which is less than 3.5. The satisfaction level only reaches the level of “general.” The satisfaction value of landscape facilities is 3.479, which is less than 3.5, and the satisfaction level is only “fair.”