Abstract: Research status on the stability evaluation and control technology of coal goaf foundation is introduced.General situation of buildings in coal dressing plant of Chengde Xinlong Mining Co.，Ltd.and mined-out area are analyzed to evaluate the threatening of mined-out area existence to the construction and use of buildings.Through calculating the relationship between the building load influence depth and the fracture zone height，the coal goaf that needs to be treated are determined，and the goaf governance design is proposed.Finally，the testing such as drilling and exploration indicated that the actual grouting effect is good，the assessment and design scheme of mined-out area can well provide guidance for the goaf grouting treatment and construction project.

Key words: Multi-layer inclined seam, Mined-out area, The foundation stability evaluation, Goaf treatment design