Abstract: Surveying and mapping is an important part of the construction of projects, which runs through the entire life cycle of the entire project construction from planning, design, construction and completion. In recent years, engineering has begun to consider the whole process of using digital twins for project management applications.Traditional measurement methods have the defects of need long work time and single results,and it's difficult to visualize. In this paper, Trimble SX10 3D image laser scanner and UAV are used for air-ground integrated measurement, the corresponding technical methods and processes are summarized, which not only shortens the mapping cycle compared with traditional measurement methods, and the problem of night optical mapping is soved, but also the results can be digitally visualized.

Key words: 3D laser scanning, air-ground integration, completion surveying, digital twin