High-efficiency gas extraction device for low-permeability coal seam

The utility model discloses an efficient gas extraction device for a low-permeability coal seam. The efficient gas extraction device comprises a gas extraction mechanism, the top end of the outer protection pipe is fixedly installed on the bottom face of the gas extraction mechanism, the bottom end of the outer protection pipe extends into a drilling well, the top of the outer protection pipe is fixedly sleeved with an outer supporting ring, and the outer wall of the outer supporting ring is tightly attached to the inner wall of the drilling well; and the drainage pipe is arranged in the outer protection pipe, and the top end of the drainage pipe is fixedly communicated with the gas extraction end of the gas extraction mechanism. According to the device, the rock stratum cracking assembly is installed at the bottom of the outer protection pipe, when an electric cylinder is in a retraction state, a spring is pressed and deformed under the action of pressure, when the electric cylinder stretches out instantly,