Abstract: Based on great potential safety hazard of work space with the mining condition of close distance coal seams and hard roof, the discrete element calculation software is adopted to research laws of strata movement and characteristics of roof stress evolution. The results shows that the rock falling formations of clastic rock, upper and lower siltstone are respectively "W" type, "V" type and "U" type, and that is associated with potential energy; the upper and lower hard roof moves cooperatively during early mining and a abscission layer between them will appear at 70 m, in addition, two sudden breaking-off occurs at 90 m and 110 m; the change of horizontal stress and vertical stress between roof rocks affects rocks' fracture, bending and rotation movement.