Abstract: Aiming at the high gas content at the wellhead and drainage outlet of coalbed methane well site, which affects the normal safety production and is a serious waste of resources. The shortages of the existing wellhead sealing device and water pipeline gas separation device are analyzed, the gas collection technology for the coalbed methane well site is proposed. The self-adjusting deflected wellhead sealing device and the water pipeline gas separation and collection device are introduced, and the process flow of gas separation and collection in gas- containing water pipeline of coalbed methane well is designed. The simulation test shows that the simulation test shows that the technology can separate and pressurize the gas in the gas-liquid mixture up to 0.2 MPa, which verifies the feasibility of this technology.