In order to implement the deployment requirements of the State Council on deepening the reform to streamline administration, to delegate powers and improve regulation and services, and to optimize the business environment, the study sets the goal of promoting the modernization of the government's governance system and governance capacity, and aims at solving the problems including the long period of project approval, the high cost of institutional transactions, the large amount of data submitted for approval of engineering construction projects, and the complexity of attachments. A BIM-based auxiliary approval management system for projects is developed by optimizing the existing project approval platform. Through the model lightweight and extraction of prefabricated parameters, the system is able to extract the data, drawings and images needed in the approval process from the collected information, and convert them into the forms needed for approval to form intelligent charts submission to the approval platform. The system is able to provide automatic calculation data for the original approval system, realize auxiliary approval and intelligent supervision, collect dynamic data of construction project design, construction and maintenance, and realize information management for the whole life cycle of construction project.