Abstract: It is difficult to realize mechanized mining for steeply inclined coal seams with dip angle greater than 70° and seam thickness of 3～5 m.Through the use of flexible shield supports and the rotary drum cutter,the pseudo inclined mechanized retreating-longwall mining method with flexible shield support and milling excavation technology (RLFM) is proposed.In the steeply inclined coal seam with an dip angle of 80° in the Hongli Coal Mine,a pseudo inclined longwall working face was arranged.The upper roadway was used as return air and the lower roadway was served as transportation.The rotary drum cutter was composed of seven parts,such as the cutting unit,the pushing unit,the frame unit,et al,which realized the mechanical milling in steeply inclined seam.Enamel chutes were laid on the working face and the broken coal transported downwards from the enamel chute under gravity.The flexible supports were arranged in groups in a pseudo inclined working face and gradually moved downward with the coal mining to form a stable recovery space.The proposed and applied mechanized mining method for steeply inclined coal seams has truly realized the mechanization of mining under such seam conditions.