The difficulties of gas control are greatly overcome by coal bed crossing drilling for in-advance extraction in soft coal seam. But the hard rocks in roof and floor in some parts of the coal mine influence the drilling efficiency. According to the superiorities of geological core drilling, the hydro hammer was combined with PDC bit in the construction of coal bed crossing gas drainage hole in underground coal mine. Through the field practice in Panyi coal mine, it is proved that the drilling efficiency is improved by 83% comparing with the traditional rotary drilling and the service life increases nearly 5 times. In addition, by using water for flushing medium, there is no dust pollution with small noise. This technology is suitable for the construction in narrow space in mine roadway.