Abstract: In order to improve the underground ventilation effect in the large-scale trackless mechanized mine,the air volume required by trackless equipment in running was analyzed.Compared with the minimum dusting air speed in working face,and the air volume as maximum personals working at the same time,the minimum underground air-supply volume was determined; Ventilation network graph for underground mine was constructed based on Vensim software,and the wind flow path,fan parameters and structures were dynamically adjusted to realize more air volume for more trackless equipment,so as to achieve the purpose of optimizing the mine ventilation system.The ventilation effect in a large-scale trackless mechanized mine in Guizhou showed that the trackless equipment needs most of air volume,which are considered as the minimum ventilation volume of underground mine; In combination with Vensim ventilation network diagram,the positions of the fan and the structures were determined,and the air door opening and fan speed were dynamically adjusted to optimize the wind flow path and air volume; The rigid duct can greatly reduce the ventilation resistance.The optimization from several aspects above can improve ventilation effect of the large mechanized underground metal mine.

Key words: Large-scale mechanized, Metal mine, Ventilation system, Optimization