The preparation of bill of quantities is the basic work of project cost management. The traditional methods faces difficulties in two aspects. On the one hand, it is time-consuming with low accuracy, and easy to miss items; and on the other hand, it is impossible to trace and query the bill quantity filled in. The integration of BIM Technology and database technology is able to use the database platform provided by BIM, applying the attribute information of model components extracted from Revit secondary development to realize the visual traceability query of bill quantity. Such method ensures the compliance of bill of quantities filling and improves the efficiency and accuracy of bill of quantities preparation. At last, the feasibility of the system is also verified by the actual project.