In order to solve the problems of low data processing efficiency and information islands in traditional construction sites, a smart construction site data collaborative processing system based on BIM (Building Information Modeling) and cloud computing is introduced to enhance the data sharing and real-time processing capabilities of engineering projects. First, the construction site's building information modeling is carried out based on BIM technology, covering the site's floor plan, structural diagram, equipment layout and other information, and is fully displayed through a three-dimensional model. Then, a cloud computing platform is built to store and process data from various sensors, monitoring equipment and personnel management systems on the construction site in real time, ensuring efficient data upload and access. Finally, a data collaborative processing mechanism is developed to enable real-time information sharing between different departments, supporting project progress monitoring, problem feedback, and resource scheduling optimization. The information sharing efficiency started at 1.4 MB/min, and after several experimental stages, it finally reached 1.9 MB/min in stage 10. The application of the collaborative processing mechanism significantly improved the communication efficiency and decision-making quality among various links, and promoted the orderly advancement of the project progress and the guarantee of construction quality. The smart construction site data collaborative processing system based on BIM and cloud computing can significantly improve data processing efficiency and information sharing level in practical applications, provide accurate data support for construction site management, and enhance the intelligence and automation level of construction management, and has broad application prospects.