Abstract: In order to solve the air disorder in main shaft of Qinggangping coal mine, the law of air pressure balance was used to analyze the ventilation system, and derived discriminant of the air disorder. The real data is used to verify the discriminant which was measured in mine ventilation resistance and natural ventilating pressure. Combining the discriminant and the practical situation, the measure was provided to prevent the air disorder. After applying the method, the airflow direction was normal when the natural ventilating pressure reached a maximum, which enhanced stability of the mine ventilation system and improved its ability of fighting against disaster.