Abstract: In order to solve the problem that BIM design calculation integration is difficult to be implemented, this study proposes a solution for cost control of design process based on BIM (Building Information Modeling). By integrating the three core modules of "one set of data, one system, and one platform", it effectively resolves issues related to insufficient model depth and continuous changes during the design process. Furthermore, it establishes seamless data connections between the cost database and calculation system, enabling rapid and accurate extraction of engineering quantities from the design model and their conversion into intuitive price data. Additionally, an advanced approach combining big data measurement with physical component quantity is adopted to generate real-time comprehensive index report data. Algorithm optimization combined with the cost database enables early-warning analysis of cost indices.