Abstract: In order to solve the serious water inrush problems in Zhaogu 1st mine, in this paper, we predict the damage depth of 11111 working face floor through empirical formula, theoretical calculation and the numerical simulation software UDEC respectively, according to the hydrological and geological conditions. Evaluate the water inrush of aquifer L8, L2 and the Ordovician limestone by the water inrush coefficient method. Propose bottom grouting reinforcement scheme aiming at aquifer have a risk of water inrush, and evaluate the floor stability after grouting reinforcement. The results show that the floor damage depth is up to 24.05m when the 11111 face take fully mechanized, which is closed to the distance between L8 limestone aquifer and 21 coal seam; The working face face the danger of water inrush from L8 limestone aquifer, and the grouting reinforcement should be carried out before mining; After grouting reinforcement, the floor damage depth and the water inrush risk reduced obviously, which is of great significance to the safe and efficient mining of the working face. The changes of 11111 working face water inflow through the locale measurement show that, the maximum inflow of working face for the 44.6m3/h, with no water inrush accidents. In a word: the prediction and evaluation of grouting reinforcement scheme is accurate and reliable, the effect is obvious and has guiding significance to the working face safety mining prediction which have similar future .