Abstract: According to the geological conditions and coal seam occurrence characteristics of Huoerxinhe Coal Mine, the paper analyzes that using once mining full-thickness mechanized mining with large mining height is a kind of coal mining technology with growing potential, which can increase economies of scale under such coal geological conditions. Through engineering analogy under the similar conditions and establishing FLAC^3D mode to process the numerical simulation, the paper demonstrates the feasibility of using fully-mechanized mining with large mining height in No. 3 coal seam of Huoerxinhe Coal Mine, carries out the optimization design for original mining technology, and achieves fully-mechanized mining with large mining height, which maximally improves the recovery rate of mine resources, and sufficiently utilizes current mining equipments, maximizes economic benefits of the mine.