A garbage compression mechanism of a garbage cleaning ship belongs to the field of garbage cleaning equipment. Including the garbage compression box, the garbage compression box is a box surrounded by the front end plate, the rear end plate, the left side plate, the right side plate and the bottom plate; the first hydraulic cylinder is installed at the center of the lower part of the rear end plate, and the waste compression box A compression head is provided in conjunction with it, and the piston rod end of the first hydraulic cylinder is connected to the compression head. A horizontally arranged reel is installed on the rear end plate above the first hydraulic cylinder, and a buffer stop roll is wound on the reel. One end is connected with a driving motor, and the middle part of the rear end plate is provided with a transverse groove, and the free end of the buffer blocking roll passes through the transverse groove and is connected with the compression head. The garbage is transported into the garbage compression box through the conveying device, the first hydraulic cylinder is activated to drive the compression head to compress the garbage forward, and the water in the garbage flows out of the garbage compression box through the compressed water outlets on both sides of the front floor, so as to compress the garbage volume and reduce the water content of the garbage rate purposes.