Air supply and exhaust duct structure of extra-long abrupt slope tunnel and construction method of air supply and exhaust duct structure

The invention discloses an extra-long abrupt slope tunnel air supply and exhaust duct structure and a construction method thereof to ensure tunnel construction safety and operation ventilation quality, improve tunnel construction efficiency and effectively solve the operation ventilation and construction problems of an abrupt slope extra-long tunnel. Comprising a left hole serving as an uphill tunnel and a right hole serving as a downhill tunnel, and further comprises a ventilation inclined shaft, a left hole connection exhaust duct and a right hole connection exhaust duct, the outer end of the ventilation inclined shaft leads to the ground, and a middle partition wall is arranged in the middle of the ventilation inclined shaft to divide the ventilation inclined shaft into an inclined shaft air supply duct and an inclined shaft exhaust duct; one end of the right hole connection exhaust duct is connected with the right hole, the other end of the right hole connection exhaust duct is connected with the ventilat