Abstract: In view of the low oxygen problem in the return air corner of 22104 working face in Shangwan coal mine, the source and emission reason of low oxygen gas are studied, and the influence law of surface atmospheric pressure and temperature change on gas emission in goaf is analyzed. The results show that the low oxygen in the working face of 22104 is caused by the high nitrogen content in the CO2-N2 zone of the coal seam, and the oxygen consumption by oxidation of the left coal, resulting in a large amount of nitrogen in the goaf. Under the influence of mining, the surface fissure is easy to form an air leakage channel with the goaf, making the low oxygen gas in the goaf migrate to the return air side of the working face, resulting in abnormal gas concentration at the return air corner. Based on the analysis of the causes of low oxygen, the pressure difference between the working face and the goaf is balanced by the pressure equalization ventilation technology, so as to reduce the air leakage and low oxygen gas emission from the goaf to the working face, keep the oxygen concentration in the working face at a normal level, provide technical guidance for the treatment of low oxygen at the return air corner of the working face, and realize the safe and efficient production of the mine.