Abstract: The elevations of the flat tunnel openings of the mines developed by the flat tunnels are different,resulting in different temperatures and pressures at each tunnel opening.And the alpine weather conditions make the impact more obvious.The changing natural wind pressure is very easy to cause the instability of the wind direction and air volume in the underground mine,which makes it difficult to ventilate the mine.A mine developed by a flat tunnel in an alpine environment in Sichuan Province is greatly affected by natural wind pressure,and there are still problems such as poor return air lines.For this reason,two ventilation technical solutions have been formulated.The first option is a ventilation method based on the diagonal extraction of the air shafts on the east and west wings,and the second option is the ventilation method of air intake from the east and west wings and the central return air.The technical and economic indicators of the two schemes are compared,including ventilation resistance,engineering quantity,equipment and operating costs.It turns out that considering the ventilation effect,investment cost and energy saving,the first one is the best ventilation solution.

Key words: alpine environment,ventilation system,natural wind pressure