Abstract: It is difficult for the hard roof to collapse in the initial mining period of a mine 3407 working face, which is easy to cause problems such as support impact load, roof impact pressure and abnormal emission of toxic and harmful gases, by measuring the mechanical parameters of the coal seam and its roof and floor on the working face, detecting the mineral composition of basic roof fine sandstone and conducting a water-filled air drying experiment on it, ANSYS/LS-DYNA software was used to simulate the development of rock fractures after blasting, to formulate the plan of deep hole pre-splitting blasting, the borehole after blasting is peeped by rock hole detector, to observe the load change of hydraulic support on the working face during the initial mining period. The results show that water has very little damage to basic roof fine sandstone, LS-DYNA software blasting numerical simulation 3.5 m hole spacing can form roof penetration cracks, after cutting the top of 3407 working face by deep hole pre-splitting blasting, the initial pressure step distance of basic roof is 21.6 m, 9.6 m less than the previous working face, more than 5 600 t coal mining, the recovery rate increased by 14.4%, it not only solved the problem of large area hanging roof of hard roof in the early mining period, but also improved the coal recovery rate in the early mining period.