How to integrate engineering cost to design accurate and efficient cost calculation methods? Nowadays, the cost calculation process is very complicated and prone to errors, which is very unfriendly to engineering cost calculation personnel. This study is based on experimental verification and integrates BIM models with engineering cost calculation tools by constructing an integrated system based on a cloud computing platform. For this purpose, the life cycle cost can be used as the main model for cost calculation in this article, and the calculation of the cost process has been deduced. The performance of the model has also been tested. A large amount of data was collected before the test, and the performance and effect were evaluated. The research results indicate that the accuracy of cost calculation in this article is between 95–99%, and the integrated system of BIM based on cloud computing and engineering cost calculation shows a high level of cost calculation accuracy.