Abstract: Taking a large domestic coal mine working face crossing abandoned roadway as the engineering background, and the stability mechanics model is set up based on the analysis of working face roof physical model. On the basis of analysis of roof stability and the stability of coal pillar, and through numerical calculation and on-site observation, research shows that the greater of mining height and control distance from the top is, the greater of the roof subsidence is under the same conditions; the stability that working face passes through abandoned roadway is affected by coal body support and face support, supporting capacity and properties affect the stability of the roof structure; working face crossing abandoned roadway should keep working face and the abandoned roadway trend to tilt in advance, and try to reduce the mining height broken; FRP bolt support should be used for two walls of abandoned roadway in order to improve the bearing capacity of coal, hydraulic pillar is used to support roof when working face is close to abandoned roadway.