An air passage device of a refrigerator, comprising an air passage cover plate configured to be arranged in front of a rear wall of a refrigerator inner tank and air passage foam configured to be arranged between a refrigerator inner tank and the air passage cover plate, the air passage foam defining an air passage, and the air passage device being characterized by further comprising at least one air door, wherein the air door comprises: a base plate part which is rotatably attached to the inner wall of the air passage cover plate, and is located between the air passage foam and the air passage cover plate, and is located outside the air passage, and is provided with at least one arcuate guide hole and an elongate through hole parallel with the arcuate guide hole, wherein a hole wall of at least a part of the arcuate guide holes is provided with multiple limiting portions, and the elongate through hole is arranged close to the side at which the hole wall is provided with the limiting portions; the front surface of the base plate part is provided with a circular knob, the circular knob and the base plate part are of an integral member made by an integral formation process, the air passage cover plate is provided with a make-way hole to allow the circular knob to extend out; and a shielding part which extends rearwards into the air passage from an edge of the base plate part and is configured to adjust the ventilation area of the air passage when being rotated along with the base plate part, wherein the inner wall of the air passage cover plate extends rearwards to form at least one guide column, which is inserted into a corresponding arcuate guide hole and cooperates with the arcuate guide hole by interference fit so that when the base plate part rotates, the hole wall of the arcuate guide hole close to the elongate through hole is elastically deformed to cause the guide column to enter the limiting portion to limit the rotation freedom of the base plate part. a base plate part which is rotatably attached to the inner wall of the air passage cover plate, and is located between the air passage foam and the air passage cover plate, and is located outside the air passage, and is provided with at least one arcuate guide hole and an elongate through hole parallel with the arcuate guide hole, wherein a hole wall of at least a part of the arcuate guide holes is provided with multiple limiting portions, and the elongate through hole is arranged close to the side at which the hole wall is provided with the limiting portions; the front surface of the base plate part is provided with a circular knob, the circular knob and the base plate part are of an integral member made by an integral formation process, the air passage cover plate is provided with a make-way hole to allow the circular knob to extend out; and a shielding part which extends rearwards into the air passage from an edge of the base plate part and is configured to adjust the ventilation area of the air passage when being rotated along with the base plate part, wherein the inner wall of the air passage cover plate extends rearwards to form at least one guide column, which is inserted into a corresponding arcuate guide hole and cooperates with the arcuate guide hole by interference fit so that when the base plate part rotates, the hole wall of the arcuate guide hole close to the elongate through hole is elastically deformed to cause the guide column to enter the limiting portion to limit the rotation freedom of the base plate part.