The LNG liquefied and rectified from oxygen-coalbed gas contains oxygen. As the decalescence or pressure reduction, the oxygenated LNG will be gasified. The gas composition is related to methane concentration in LNG, storage pressure, heat absorption or pressure reduction. HYSYS software was used to simulate the gas components of oxygenated LNG gasification. It is found that the higher the methane concentration in LNG, the higher the methane concentration in the gas phase after gasification; when the gasification amount or pressure reduction of LNG is smaller, the concentration of the non methane component in gas phase is higher, and the methane concentration in gas phase increases with the increase of gasification amount or pressure reduction; the nitrogen concentration in LNG has a great influence on the oxygen concentration in the gas phase; under the same gasification rate or pressure reduction, the higher the LNG storage pressure is, the higher the methane concentration in the gas phase is.