Building tunnel ventilation system

The utility model discloses a building tunnel ventilation system, including fixing base, air inlet spare, transition piece, fan, air -out piece, air inlet spare is fixed on the fixing base with the air -out piece, and the fan is fixed in a transition inside, air inlet spare and air -out piece are loudspeaker form and arranging in a transition both sides as to this, the transition piece is including the round cylinder part, hand pole, the connection piece that have the breach, the hand pole becomes the arc, and the one of which end hinge connects the one end at circle cylinder part's breach, and middle end is articulated with the one end of connection piece, the connection piece is the arc, and the other end of connection piece is articulated with the other end of circle cylinder part's breach, the wind wheel includes conical wheel hub, a plurality of blade, a plurality of subsidiary leaf, blade distribution assists the leaf and fixes on wheel hub and be in between the well lower part of per two adjacent blade