Abstract: In the engineering background of preventing the support crushing and water inrush accidents of 8₂22 working face in Qi dong Coal Mine, this paper studies the implementation effect of deep hole pre-splitting blasting in preventing the accidents under unconsolidated confined aquifer based on the mechanism of roof pre-splitting blasting. The design method based on the location of key stratum was proposed; the test measures such as pressure measurement, change of long hole water linkage type and borehole imaging were proposed and applied in field. The decrease of weighting step and duration, the increase of the water level fluctuation period and the development of the fractures in the hole proves the effectiveness of this technique. These achievements guarantee the safety mining of 8₂22 working face.