Abstract: Seasonal climate change affects the magnitude and direction of the natural wind pressure in the mine, and if the natural wind pressure is properly used as a driving force, it will be beneficial to energy saving and emission reduction in mine ventilation system. In the initial design of the underground ventilation system of Yanqianshan Iron Mine, the use of natural wind pressure is relatively small, and the selection of fans does not take into account the factors of seasonal climate change, through the study of the seasonal climate change in Yanqianshan Area on the impact of mine ventilation law, and use this law to guide the optimization of underground base station fans. Through the 3D simulation system to establish the underground ventilation system model, simulate the climate conditions of Yanqianshan Area throughout the year, through the wind flow simulation to calculate the magnitude and direction of the natural wind pressure at the inlet shaft, the results show that Yanqianshan Area in the summer daytime, the No.1, No.2 main inlet shafts will appear with the mine ventilation direction of the reverse of the natural wind pressure, the rest of the seasons at the inlet shafts of the natural wind pressure is conducive to ventilation, in which the natural wind pressure in winter can be exploited the value of the natural wind pressure in winter is the largest, and the wind pressure of the fan in winter is significantly higher than that in summer, which makes the total air intake in winter by 4.46%. It is recommended to adjust the working condition of K-8-19 fan at 2-3 and 2-4 base station of the main station and K-8-23 fan at 2-15 and 2-16 base station of the main station, and to adjust the mounting angle of the main fan blades from 35° to 30° in winter, and to adjust the main fan blades from 35° to 30°. According to the changing law of seasonal climate change of Yanqianshan Area, the working point of the main fan is adjusted at the right time, and the natural wind pressure is effectively used, which solves the problem of excess air volume of the mine ventilation system in winter, and achieves to satisfy the needs of mine ventilation in a more energy saving way.