Abstract: For dealing with the safety problems caused by roof separation, we analyze its mechanism, optimize roadway support and give early warning to such accidents.Based on the engineering background of a working face material roadway in Sipan area of a mine, the influences of roadway span, height, ground stress and bending stiffness of surrounding rock are analyzed through theoretical analysis and numerical simulation.The pseudo-roof height and direct roof separation height are obtained at 43 m through numerical simulation, and combined support with anchor net beam is adopted according to the supporting mechanism of large-section roadway.High prestressed anchor cable and grouting bolt cable are used to optimize support and grouting maintenance in the broken separated layer area, which greatly reduces the amount of roof separation, the breaking of key layer and the surface settlement caused by the separated layer.The roadway safety is greatly improved by monitoring according to the critical value and early warning value of the roof separation layer.