The invention discloses a hydraulic
cutting device and a hydraulic
cutting method for drilling through a
bed. The hydraulic
cutting device for drilling through the
bed comprises a water tank, a water inlet
pipe, a water pump, a water outlet
pipe, a rotating water
tail, a drilling
machine, a drilling rod and a hydraulic cutting
drill; one end of the water inlet
pipe extends into the water tank, and the other end of the water inlet pipe is connected with a water inlet of the water pump; one end of the water outlet pipe is connected with a water outlet of the water pump, the other end of the water outlet pipe is connected with one end of the drilling rod through the rotating water
tail, the other end of the drilling rod is connected with the hydraulic cutting
drill, and the drilling rod is arranged on the drilling
machine and is driven by the drilling
machine to rotate; and a pressure gage is arranged on the water outlet pipe, and a pressure regulating valve is arranged on the water outlet pipe between the pressure gage and the water outlet of the water pump. The hydraulic cutting device for drilling through the
bed has the advantages that a drilling
coal section is reamed by using the cutting action of
high pressure water jet, the area of a
coal body exposed in the hole is increased, a fracture is manufactured, the gas permeability of the
coal bed is improved, so that the gas extraction effect is improved.