Based on increasingly ventilation area, insufficient ventilation coefficient, ventilation route extension, ventilation resistance increase problem, through the comprehensive analysis of ventilation system in Nanjing Mine, 3 transformation scheme of mine ventilation system was put forward. Through the comparison, the main fat machine was set in the northeast of main shaft. By internet calculation, the ventilation system after transformation met the needs of mine air quantity and air resistance, which realized the stable and reliable ventilation system.