The stability of mining roadway is affected significantly by the condition of the surrounding rock and stress regime, which is the key factor for determining the roadway support program. Located in syncline axis, the No.15 seam is a steep seam at - 230 m level in Changgouyu coal mine, the original flexible shield cannot meet the safety and production requirement. The No.15 seam is classified as unstable and relatively complex according to the analytic hierarchy process (AHP). The distribution characteristics of stress in the seam around the synclinal axis before and after mining are analysed by use of FLAC2D. According to the complexity of the coal seam and the stress distribution characteristics, the supporting parameters using bolt-mesh-anchor were selected and implemented successfully in an underground roadway, which can be referred to as in the design of roadway support in similar complicated coal seams.