Abstract: Complex irregular theme parks and conventional public buildings have high construction requirements in terms of diverse styling, numerous specialized systems, and customer experience. To address the challenges that traditional construction methods cannot solve, it is necessary to adopt BIM-based digital construction methods. This paper focuses on the characteristics of large-scale international theme park decoration projects, such as the lack of construction standards, diverse irregular components, and frequent creative changes. It introduces the application of BIM-integrated technology in decoration projects, conducting research and application in three aspects: modeling and optimization of irregular thematic packaging, prefabrication of components, and digital construction. This ensures the successful implementation of the decoration project and provides references for the application of BIM technology in other cultural tourism decoration projects.