In order to improve the bad mine circumstance and ensure the safety of the mine production，the ventilation system must maintain the best operating status.It takes the ventilation system in Baolun gold mine as the study subject，through the investigation and determination of the ventilation system，the problems existing in the underground ventilation system are as follows： the total air volume is insufficient，poor stope ventilation，low efficiency of the main fan，a large amount of air leakage in the mined area，etc.The underground ventilation system was severely disrupted，which seriously influenced the safety in production.Through computer networks resolving and optimization analysis，the ventilation system is optimized and the optimization scheme is put forward.The results show that the effect of optimized mine ventilation system is obviously enhanced，and the total air volume of mine is obviously increased.The fan station efficiency is 83.1%，the compliance of wind speed is 87.5%，the effective air volume rate is 73.7%，and the average temperature of mining surface is 26.3 ℃.The optimization scheme improves the underground ventilation conditions and solves the existing problems of the ventilation system in Baolun gold mine.