Abstract: Before the initial operation of metro tunnels, the construction quality and zero-state of tunnels need to be inspected. The traditional method uses a total station to measure feature points and sections of tunnel, which is heavy-workload, low-efficiency and single-result.To solve the above problems,this paper proposes a mobile laser scanning 3D point cloud reconstruction method for metro tunnels based on inertial navigation and CPⅢ control points, and then verifies the accuracy of point cloud of tunnel section,central axis and track centers, which meets the requirements of tunnel planning acceptance measurement. At the same time, this method can simultaneously obtain the horizontal diameter, pipe wall image, vertical section and cross section of the tunnel, which not only improves the operation efficiency, but also can be used as the zero state file of rail transit structure, so as to provide detailed basic data for metro tunnel tunnel planning acceptance measurement and later operation and maintenance.

Key words: metro tunnels, mobile laser scanning, inertial navigation, planning acceptance measurement, 3D point cloud