Abstract: For the actual project that 1307 large mining face of Zhaozhuang Coal Industry has a weak composite roof which is easy to collapse, according to the scene observation and the numerical simulation, the key factors of roof collapsing is analyzed, and the reinforcement scheme of pre-grouting in advanced deep hole of two coal roadways is adopted, and the reasonable reinforcement layer and the best grouting time are analyzed. A kind of grouting material with high permeability is selected to carry out grouting reinforcement. After the grouting, the rib spalling and roof fall of the working face were obviously improved, the amount of chemical slurry was greatly reduced, and the safe and rapid recovery was realized.