Abstract: According to the 3D laser scanning engineering applications in the mined -out area underground space, combining with Geomagic software and 3DMINE software, the field operation and management method is analyzed and summarized aiming at the problems encountered in the measurement and the later space point cloud data processing. The scheme of measuring complex mined-out area is established with a set of relatively simple, efficient processing of cloud point and 3D modeling process; the measurement data is obtained effectively with the application in Fujian Yuan Xin mining cavity scanning; the model of the cavity and tunnel integration is established after the simplification and optimization of the point cloud data to verify the location, morphology and distribution which provides effective support for the comprehensive management of coal mined out area and later remaining pillar stopping. The research result provides a good reference for the similar cavity treatment.