Abstract: In order to get the accurate gas emission quantity of gas emission sources in fully mechanized working face, the research method is based on the combination of field measurement and mathematical calculation model. Taking 14205 fully mechanized face of Shaqu Coal Mine as the research object, in this paper, the gas concentration and wind speed of the fully mechanized working face were measured by piecewise measurement method. Based on the measured data, by using calculation model of gas emission sub-source in fully mechanized coal face, gas emission of coal wall and broken coal and gas emission laws of gob were researched during the maintenance period. The results obtained by calculation showed that gas emission rate of coal wall and broken coal accounted for 61.2% of the total gas emission rate of fully mechanized coal face, and gas emission rate of gob accounted for 38.8% of the total gas emission rate of fully mechanized coal face.