Abstract: In order to find more efficient power generation of ultra-low methane gas concentrations of coal mine, the efficiency of different concentrations of coal mine ventilation air methane in different power generation ways of steam generation, gas turbine power generation were calculated，the results show that the efficiency of multi-stage compression with intermediate cooling of the gas turbine power generation with the regenerator is highest, when the methane concentration exceeds 1%, the highest efficiency even more than 50%. Using a gas turbine power generation system, also have good features of simple structure and does not consume water.