Abstarct: Abstract Ventilation is one of the most important steps in underground mining operations, and its incorrect implementation causes danger and serious damage to the health of workers and even machines. Today, with the advancement of technology and the reduction of resources close to the surface of the earth, the depth of underground coal mines is increasing, which itself causes the problem of ventilation to become more critical and the problems of designing and implementing the ventilation system increase. If, for any reason, the level of pollutants in the air of the mine reaches more than the permissible level baxsed on the existing standards, the dilution of the pollutants is done by using ventilation. For this purpose, by means of mechanical systems, they direct the flow of clean air outside the tunnel with appropriate pressure and flow into the tunnel and the underground spaces created due to mining operations. In some cases, the presence of tunnel equipment, the traffic of mine workers, the movement of machines inside the tunnels, such as locomotives and wagons transporting minerals, as well as the facilities inside the tunnel, cause disturbances in the ventilation network and changes in the air flow. In this research, the effect of the mentioned items on the ventilation of the tunnel was investigated experimentally in the Tezreh mine, which is one of the old mines of the Eastern Alborz Coal Company, and the results of the measurements in different conditions were recorded. The ventilation of this mine has been investigated using the simulation software (ventsim) and in two cases without the presence of locomotives and obstacles and with the presence of locomotives and obstacles and the results have been compared with the experimental method. The results of different states of flow intensity distribution and the amount of suitable air for ventilation, taking into account the ventilation equipment, show that the presence of moving obstacles such as locomotives and wagons carrying materials and minerals can have a significant effect on the flow intensity. in the mine ventilation network. Considering the changes made and their amount, the results can be used to design and implement changes in the ventilation network.