Abstract: The roof system of the four pavilions and one center project in Nanchong needs to create a cultural impression of the silk capital and show the curved shape of "butterfly flying", it brings many challenges to the construction of the roof which is different from the conventional roof. In this project, the principle of differential approximation was used to transform free-form surface into a combination of surface and bevel. Through BIM technology, the design and installation of free-form surface metal roof panel was effectively solved. The problem of coordinated displacement of metal roof and main structure was solved by setting plug-in movable joints at adjacent sections of main keel. Through the comprehensive application of measurement data and BIM model, the size of connector was automatically generated. A kind of fast and convenient measuring scale was designed and manufactured, which solves the problem of free-form surface space measurement. The project used the cruciform guiding rule and rubber gasket to install the aluminum plate,which could ensure the slot width and smoothness between plates. Through the innovation and comprehensive application of techniques, the construction accuracy was improved, the construction period was shortened, and the installation cost was saved.