Hydraulics design is important for achieving the maximum bit hydraulic horsepower or jet impact force and improving the bottom hole cleaning. The existing hydraulic parameters design method is suitable for the low pump capacity. As the large-power-and-high-pressure pump is widely used on the drilling site, the existing hydraulic parameters design method is not sufficient to make the drill bit obtain the maximum hydraulic energy. In this paper, a new hydraulics design method is presented, and a larger bit hydraulic horsepower can be achieved compared to the existing design method. A contrastive analysis under different modes of pump pressures is conducted using the new design method, which shows that the improvement of the limited pump pressure can significantly increase the bit hydraulic horsepower. The circulating system pressure bearing capacity should be improved as much as possible.