Abstract: In the process of reconstruction of existing commercial complexes, problems such as lack of data, low efficiency of collaboration and large construction interference are often faced. In order to solve these problems, this study aims to explore the application path of intelligent construction technology in the transformation of commercial complexes, in order to improve the efficiency and quality of transformation and promote the efficient and intelligent development of urban renewal. This project takes the upgrading of Guangzhou Tianhe City Shopping Center as an example. In view of the challenges such as the lack of existing building data, the complexity of electromechanical systems, and the harsh operating conditions, a ' scanning-modeling-analysis-optimization ' whole process technology system was constructed. High-precision scanning is completed by a three-dimensional laser scanner to obtain accurate field data. Based on the Revit platform, the civil and electromechanical BIM models are reconstructed, and 500 structural electromechanical details are integrated. With the help of BIM model, the transformation scheme of smallpox is verified, and optimization suggestions are put forward to realize the transformation and improvement of smallpox net height. The application of the project shows that BIM and 3D laser scanning technology play an important role in the transformation of commercial complex. The high-precision data obtained by 3D laser scanner provides accurate on-site information for the transformation project and effectively solves the problem of data loss.The construction and optimization of BIM model realizes the efficient collaborative design among various professions and improves the design efficiency and quality. Through the consistency management of the model and the actual construction, the construction interference is reduced and the smooth progress of the renovation project is ensured. BIM and 3D laser scanning technology provide a reproducible digital solution for the transformation of commercial complex through precise data support, collaborative design optimization and consistent management of modeling and simulation. The technical system not only effectively solves the problems of data loss, low coordination efficiency and large construction interference in the transformation of existing commercial complexes, but also promotes the development of urban renewal in the direction of high efficiency and intelligence, which has important application value.