Abstract: By similar simulation and numerical simulation methods, we study damage characteristic of thick composite roof shoulder, get the conclusion that the fissure generated in the shoulder seam and mudstone interface, developing along the edge of the shoulder anchorage zone to the deep surrounding rock, while spalling at the top of roadway's side, eventually resulting in roof collapse; with the increase of depth and the tectonic stress, plastic zone of the shoulder thin sandstone has the fastest development, is the key part of roadway stability control; side anchor cable reasonable distance from the roadway's side is 650 to 800 mm, reasonable angle is 20° to 30°, side anchor bolt reasonable angle is 10° to 20°.