Abstract:BIM technology relies on digital modeling, information integration and dynamic analysis capabilities to provide efficient and accurate technical support for cost management. This paper analyzes the phased, dynamic and data accuracy characteristics of construction project cost management, discusses the role of BIM technology in improving management continuity, enhancing dynamic flexibility and ensuring data accuracy, and discusses the application of BIM technology in optimizing cost estimation in design stage, evaluating cost changes in construction stage and verifying settlement accuracy in settlement audit stage. In order to build a scientific, efficient and intelligent construction cost management system, improve the cost control ability of the whole process, and promote the digital transformation and high-quality development of the construction industry.