Abstract: The complete drawing data is the key factor to the reinforcement and restoration of ancient architecture. The existing materials of the ancient architecture can not satisfy restoration, therefore it's urgent work to establish electronic record for ancient architecture. The traditional method is usually getting electronic record by surveying and mapping combined with CAD. There are some disadvantages such as low efficiency, high cost and new damage to ancient architecture during the measurement process. Based on the problems mentioned above, taking Guangxingli inner courtyard in Qingdao as the research object, the 3D laser scanning technology is combined with the BIM technology in order to investigate point cloud acquisition, feature lines caching, 3D model creation, so as to provide technical support for the restoration and reconstruction of damaged ancient architecture. The research shows that the technology can fulfill the modeling accuracy requirement with high efficiency, what's more, new damage during the measurement process can be avoided, furthermore, it can provide a reference for similar ancient architecture restoration.

Key words: 3D laser scanning technology, BIM technology, ancient buildings, point cloud data acquisition, feature line extraction, 3D modeling