The tunnel variable frequency fan flows the air in the tunnel, discharges the car's tail gas, and flows into fresh air. The short tunnel can be discharged quickly because of the good ventilation. The axis fans are diluted because it can dilute the cars in the tunnel during work, thereby reducing the harm of the tail gas to the human body. Another point is that if an accident or a fire occurs in the tunnel, you can turn on the tunnel axis fans according to the position of the fire point to slow the air circulation. As a result, more time to let personnel evacuate. The tunnel variable frequency fans can be excreted in the tunnel construction. Due to explosive explosives, the use of internal combustion engines, harmful gases are released in the strata during excavation. Provide a good construction environment for tunnel construction to ensure the health of operators and improve work efficiency.