Abstract: Water inrush from coal floor is one of the main disasters in mine construction and mine production, brings great risks and losses to the coal mine safe production with huge destruction, floor grouting reinforcement technology is an important measure and method for water prevention. Using directional borehole to conduct reinforcement by pre-grouting will be an important development and promotion direction of floor grouting reinforcement technology in the future. According to the characteristics of directional drilling, this paper has systematically studied selection of grouted horizon and grouting materials, grouting technology, evaluation criterion of grouting effect, grouting reinforcement technology is formed. The tests in face 11 151 of Zhaogu mine show that the grouting technology is reliable and advanced to ensure grouting and drilling, the effect of grouting reinforcement is evident, achieves the goal of reinforcement by in-advance regional grouting in working face.