This article briefly summarizes the application of BIM technology in different stages of architectural design. With respect to the characteristics of the conceptual design process at the preliminary stage, the author analyzes the strengths and weaknesses of BIM application, and provides corresponding recommendations. Then the article discusses the utilization of Artlantis in architectural visualization. Starting from BIM modeling and data transfer, the author elaborates the capability, method, tools and value in combining ArchiCAD and Artlantis in 3D rendering. Finally, the author supports further improvement of BIM application, believing such technology will further enhance the quality and efficiency in preliminary design process.