Abstract: The 3237 west above face was researched in zhaogezhuang mine in this paper,based on the geological conditions and mining technology of 3237 west above face,the gas source of 3237 west above face was analyzed.The reason of gas accumulation in this face was discussed.The drainage of the coalseam is not in an ideal situation,the drainage tecknowledge including diagonal lead roadway drainage and the drainage of high pumping in the roof was put forward to control gasin 3237 west above face,in which the diagonal lead roadway drainage plays a similar effect of Y type of ventilation system.After gas control technology was implemented,the air volume required in fully mechanized top coal caving faces lowed down from the maximum 1500m³/min to about 990m³/min,and the gas concentration was not less than 0.4% in the return airway,providing ways for safe and efficient mining working face in fully mechanized top coal caving face in big angle extra thick coal seam.