Abstract: Aiming at the problem of multi-level,long ventilation route,the complexity of ventilation roadway network system,large return air resistance in Linxi coal mine,on the basis of testing ventilation resistance and structure resistance in Linxi coal mine,the tested results show that the main cause of large ventilation resistance is too much air door and part of air door in the unreasonable position.By using the ventilation system simulation software to optimize the reasonable program of ventilation system transformation——removing the unreasonable air doors and increasing and changing partial air door.Fan operating parameters and the conditions of the underground ventilation consistent with the program results by site implementation.The total resistance reduced 123.4 Pa.The total air volume increased 22.11 m³/s.The equivalent orifice increased 0.488 m².The good result provided guarantee for the safety production in Linxi mine.