Abstract: For counter-rotating main fan, the traditional design concept of wind tunnel has been revolutionized that independent wind tunnel are set up for two main fans separately, which are connected to the air shaft and arranged side by side. Besides, the way of setting spiral control damper and pressure measuring unit inside the wind tunnel is taken, which reduced the difficulty of construction, the floor space of the wind tunnel and the external leakage of main fan compared with the original public wind tunnel. Meanwhile, the routine inspection, maintenance and switching of the main fan and its ancillary equipments become easier and favorable conditions are created for the fan performance testing and mine air reverse operations.