Abstract: In order to master the resistance distribution of the ventilation system and determine its optimization techniques in Fenghuangshan Coal Mine,a method combining the barometer method and high-precision differential pressure meter method were selected to measure the ventilation resistance,the adjustment processing and error inspection were made on the measured data and results.The results showed that the measured data were reliable,and it was found that the effective air quantity of the existing ventilation system was low,its external air leakage was large and its three-zone resistance distribution was in imbalance.Aiming at these problems,some measures were taken to optimize the ventilation system of the mine,including closing No.91,No.94,No.154 and No.155 panels,shrinking No.151 panel and changing the main return airway on No.2 level into intake airway.After optimization,the effective air quantity rate increased from 82.70% to 88.37%,and the three-zone resistance distribution was more balanced,and the ventilation system became more secure and reliable.