Abstract: With the innovation and popularization of bolting support technology, the manner of long-pillar working in the traditional system of winning and opening for working faces is being placed by small roadway driving along gob. By FLAC simulation, the bearing pressure distribution above the coal bed and the deformation of wall rock surrounding the roadway driving along gob of different size pillar under the influence of mining pressure and same way of bolting support are simulated in this paper, as a result the range of optimizing pillar size is obtained which is 4~6m.