A henhouse includes a gable, a sidewall, and a roof. An inner chamber parallel to the sidewall is provided in the middle of the henhouse. The inner chamber includes an inner wall parallel to the sidewall and an inner roof. A partition is provided between the sidewall and the inner wall. An air inlet plate is provided between the two inner walls located below the inner roof. A pressure chamber is formed between the inner roof and the air inlet plate. A premixing chamber is formed between the inner roof and the roof. A plurality of fans and air inlet windows are uniformly provided on the inner roof. A plurality of air inlet holes and small inlet windows are uniformly provided on the air inlet plate. A plurality of wet curtains and an air vent are provided on the sidewall. A plurality of air outlet slots are uniformly provided on the inner wall.