Abstract: Mined area can severely affect the mine's follow-up production planning.Based on the practice of applying 3D laser monitoring technology (CMS) to collect the underground 3D data in Dahongshan Copper Mine, a detailed introduction is made of the 3D cavity data collection method, data pre-treatment and application practice of CMS technology.This technology adopts a contactless survey method.It can not only obtain the accurate spatial parameters of finished stopes such as length, area, volume, deformation of wall rock and roof and their change relation but also greatly improve the safety and efficiency of cavity data collection, providing the data for cavity safety evaluation and control and the design of ore-pillar extraction.

Key words: CMS, Finished stopes, Data pretreatment, Point cloud