Abstract: Lacking of work space is the major difficulty probleme of the mining in thin coal seam.Some relative problems such as high labor intensity, abominable working conditions, more accidents, equipment incompatibility, the higher of input-output ratio, low efficiency and poor economic,more serious problem from insufficient space are appeared in fully mechanized face.The reasonable strenght of supporting roof is determined based on the "limited deformation"theory,and it is applied to thin coal seam N1014 "floor creeping"fully mechanized mining face successfully in Bin Lang coal mine. 　　

Key words: Extremely thin coal seam, Fully mechanized mining, Limited deformation, Roof control