An air treatment device comprising an air outlet mechanism and an air treatment device body, wherein the air treatment device body is provided with a vertical air duct, characterized in that a first upper end surface of the vertical air duct is obliquely arranged, such that the first upper end surface comprises a vertically higher side relative to other parts of the first upper end surface, and the air outlet mechanism comprises: a first air outlet plate that surrounds the higher side of the first upper end surface and is rotatably connected to the air treatment device body, and a second air outlet plate that surrounds the other parts of the first upper end surface and is connected to the air treatment device body; the first air outlet plate comprises a straight plate rotatably connected to the air treatment device body and an arc-shaped plate connected to the straight plate, an end of the second air outlet plate away from the first upper end surface is inclined toward an outer side of the air duct, an air outlet is formed between the first air outlet plate and the second air outlet plate, and the first air outlet plate is rotatable relative to the air treatment device body to adjust the air outlet; the first upper end surface of the vertical air duct is surrounded and defined by a straight edge and an arc-shaped edge, the straight edge is perpendicular to an inclination direction of the first upper end surface and is at the highest position of the first upper end surface, and the height of the arc-shaped edge gradually decreases in a direction away from the straight edge; the straight plate of the first air outlet plate is rotatably connected to the air treatment device body through a rotating shaft parallel to the straight edge, and the second air outlet plate is fixedly connected to the arc-shaped edge of the first upper end surface. a first air outlet plate that surrounds the higher side of the first upper end surface and is rotatably connected to the air treatment device body, and a second air outlet plate that surrounds the other parts of the first upper end surface and is connected to the air treatment device body; the first air outlet plate comprises a straight plate rotatably connected to the air treatment device body and an arc-shaped plate connected to the straight plate, an end of the second air outlet plate away from the first upper end surface is inclined toward an outer side of the air duct, an air outlet is formed between the first air outlet plate and the second air outlet plate, and the first air outlet plate is rotatable relative to the air treatment device body to adjust the air outlet; the first upper end surface of the vertical air duct is surrounded and defined by a straight edge and an arc-shaped edge, the straight edge is perpendicular to an inclination direction of the first upper end surface and is at the highest position of the first upper end surface, and the height of the arc-shaped edge gradually decreases in a direction away from the straight edge; the straight plate of the first air outlet plate is rotatably connected to the air treatment device body through a rotating shaft parallel to the straight edge, and the second air outlet plate is fixedly connected to the arc-shaped edge of the first upper end surface.