Abstract: in order tosolve the cal al spalling easily occurred in the high cuttingfully mechanized coal mining face and the prominent problems existed in the avaliable method to control the coal wall salling a breakthrough point to control the coal all spallig would be set on the hyarauli powered suppor. Amethod combinedwith the theoretcal analysis and the nunercal stnmulation was applied to study the infuence aw ofthe coalwall tailit when the setingload ofth fuly ehanized hydraulic powered support was 0 ～ 5 0.Ok N.The study resuits showed that when the seting load of the hyaraulic powered support was increased from 0 to 5 0.0kNthe falre depth in the coal wall would be reduced from 3.0 m to 1.5 m,the verical concentrated stress peak was reduced by 24%,the roof uosidence value at thecoalwall as reduced by 24 mm and the horizontal ofist value of the coal wall was reduced by 8 m.the stie measured resutshowed that the setig load increased ofthe powered suppot could eff ctively reduce the coal all spallig times and spalling depth. The studly resulis showed that the sting load increased of the powered support could effectively reduce the failure scope of the coal wallcould improve the stress status of the coal wall and finallyalling occurred.