Abstract: The treatment of mined-out areas plays an important role in prevention of mine geological disasters.In order to ensure safety and stability of tailings dam in Fushan Iron Mine，a three-dimensional laser detection was made for a minied-out area of iron ore to analyze its stability and the cabing risks.Then，a comprehensive management plan was proposed.After the implementation of treatment programs，some significant security risks underground the mined-out area are eliminated，and the security and stability of tailings and the normal production in mine are ensured，thus providing a reference for the treatment of other mined-out area.

Key words: Mined-out area, Tailing sand filling, Subsidence, Tailings dam, Laser scanning