Abstract: According to the danger of CO large emission from the coal mining face due to the high concentration CO gas in the goaf of the upper 2-2 seam of No.30 106 and No.30107 coal mining face in 3-1 coal seam of Longhua Mine, the polymer foam material injection, nitrogen injection and local positive pressure ventilation tec hnology were applied to eliminate the danger of the high concentration CO.The paper introduced the implemented steps of the local positive pressure ventilation techno logy and the adjustment plan of the ventilation system.With the monitoring and measuring of the ventilation pressure, ventilation quantity and the upper corner CO cont ent, the paper comprehensively evaluated the implemented effect of the local positive pressure ventilation technology.The site application showed that the application of the local positive pressure ventilation technology could keep the pressure energy difference between the mining seam and the goaf of the upper seam at about 200 Pa and could keep the CO content in the upper corner not over 24x10-6.