The utility model discloses a large-aperture quick-detachment mechanical pipe cleaning pig which belongs to the technical field of machine detachment. The large-aperture quick-detachment mechanical pipe cleaning pig comprises a first pipe cleaning device, a connecting device and a second pipe cleaning device. One end of the connecting device is connected with the first pipe cleaning device, and the other end is connected with the second pipe cleaning device. A straight rubber cup and a straight disc-shaped rubber cup are arranged on a connecting component. The first pipe cleaning device comprises a rubber cup self-locking mechanism and a rubber cup self-locking pressing mechanism. The rubber cup self-locking mechanism is arranged on the connecting device. The rubber cup self-locking mechanism contacts with the rubber cup self-locking pressing mechanism. The straight rubber cup and the straight disc-shaped rubber cup are arranged behind the rubber cup self-locking pressing mechanism. The rubber cup self-locking mechanism pushes the rubber cup self-locking pressing mechanism for pressing the straight rubber cup and the straight disc-shaped rubber cup. The large-aperture quick-detachment mechanical pipe cleaning pig provided by the utility model requires no plugging for holes and bolts in a mounting process and reduces intensity of physical labor in the mounting process.