Abstract: In this paper it studied on the lateral supporting pressure in mechanized caving face by using discrete element numerical calculation, obtained the law of pressure distribution and the reasonable position of roadway layout. It calculated the plastic zone width of the coal pillar with the theoretical calculation, determined the reasonable width of the small pillar along the roadway and analyzed the stability of the roadway. Combined with the engineering practice, it showed that the coal pillar width determined by this method was scientific and reliable, provided a scientific basis for the roadway layout along the roadway in mechanized caving face.