Abstract: By the combined method of theoretical analysis, field measurement and numerical simulation, we analyze overlying rock breaking and migration laws of a mine narrow coal pillar support, we get that the basic roof fracture location within coal pillar is 6.5 m, and the rotary sinking motion of key block B of basic roof is the root cause of roof asymmetric deforamtion and horizontal shear diastrophism and coal pillar instability and failure of roadway. The implementation of asymmetric “multi anchor cables-channel steel-reinforced beam combination” key supporting system, there is no separation phenomenon for return air roadway in 605 fully mechanized working face under the influence of mining, and roadway maintenance status is relatively stable.