The invention discloses an anchor rod
system used for gas extraction and
hydraulic fracturing and an extraction method. The anchor rod
system comprises a hollow anchor rod, a
retaining ring, a closed locking device, a gas extraction
pressure pipe, a
hydraulic fracturing system, a gas extraction system and the like. The hollow anchor rod comprises an anchoring section and a tensioning section. The anchoring section is a
solid body, the
retaining ring is arranged outside the anchor section, the
diameter of the
retaining ring is smaller than that of a drilled hole of the anchor rod, and the retaining ring serves as a connector of the anchoring section
solid body and the hollow gas extraction part of the tensioning section. The tensioning section is connected with the closed locking device through an outer thread. The gas extraction
pressure pipe is connected in the hollow anchor rod, the
diameter of the gas extraction
pressure pipe is slightly smaller than that of the hollow anchor rod, and threads are arranged on the upper end and the lower end of the gas extraction pressure
pipe to be connected with the hollow anchor rod in a threaded mode. A gas content monitoring instrument is arranged on the lower section of the gas extraction pressure
pipe. The gas extraction pressure
pipe is connected with a gas extraction pipe of the gas extraction system through a system connecting thread. Gas can be efficiently extracted in an extraction roadway, the hole sealing rate is high, gas extraction intelligence is achieved, and the dangers such as local concentrated gas burst can be effectively pre-warned and predicted.