The promotion of low-carbon city tourism is an important measure to reduce carbon emissions in various regions and realize sustainability. This research explores tourists’ sensory experience in the city’s low-carbon tourism economy, environment and society from urban low-carbon tourism and providing relevant units with a blueprint for urban low-carbon tourism planning. This research accompanies the empirical cases and introduces Gray Relational Analysis to overcome the difficulties in practice, sometimes due to cost and time constraints, that strategies must formulate with little information, little data, or uncertainty. The research results show that the top low-carbon tourism evaluations of Tainan’s business districts by tourism experts are An-Ping Business District and ChengKung University Business District. Relevant planners can refer to this ranking and weight to analyse sensory marketing opportunities to help create a more attractive low-carbon tourism city.