The invention provides a marine garbage disposal device. The marine garbage disposal device comprises a disposal box, and further comprises a smashing device used for smashing garbage, a dewatering device used for compressing and dewatering the smashed garbage and a drying device used for drying the garbage so as to reduce the weight of the garbage which are sequentially arranged from the top down. The marine garbage disposal device is small in occupied area, capable of continuously disposing the garbage and capable of achieving smashing, dewatering and drying disposal for the garbage, enablesthe garbage after being disposed to be low in weight and slight in peculiar smell, uses the smashing device for thoroughly smashing the garbage, uses a material scraping device for preventing garbageresidues from being jammed among smashing blades, uses a high pressure cleaning device for regularly performing high pressure cleaning on an extrusion bag, and uses gas jet under high pressure for blowing off the garbage residues remaining on the extrusion bag.